diff --git a/Projects/DataSource/Sources/Common/Extension/Encodable+.swift b/Projects/DataSource/Sources/Common/Extension/Encodable+.swift
new file mode 100644
index 00000000..79eba303
--- /dev/null
+++ b/Projects/DataSource/Sources/Common/Extension/Encodable+.swift
@@ -0,0 +1,18 @@
+//
+//  Encodable+.swift
+//  DataSource
+//
+//  Created by 이동현 on 8/3/25.
+//
+
+import Foundation
+
+extension Encodable {
+    var dictionary: [String: Any] {
+        guard
+            let data = try? JSONEncoder().encode(self),
+            let dictionary = try? JSONSerialization.jsonObject(with: data) as? [String: Any]
+        else { return [:] }
+        return dictionary
+    }
+}
diff --git a/Projects/DataSource/Sources/DTO/RoutineCreationDTO.swift b/Projects/DataSource/Sources/DTO/RoutineCreationDTO.swift
new file mode 100644
index 00000000..a499368f
--- /dev/null
+++ b/Projects/DataSource/Sources/DTO/RoutineCreationDTO.swift
@@ -0,0 +1,13 @@
+//
+//  RoutienCreationDTO.swift
+//  DataSource
+//
+//  Created by 이동현 on 8/3/25.
+//
+
+struct RoutineCreationDTO: Codable {
+    let routineName: String
+    let repeatDay: [String]
+    let executionTime: String
+    let subRoutineName: [String]
+}
diff --git a/Projects/DataSource/Sources/DTO/RoutineResponseDTO.swift b/Projects/DataSource/Sources/DTO/RoutineResponseDTO.swift
index ab867295..3373662e 100644
--- a/Projects/DataSource/Sources/DTO/RoutineResponseDTO.swift
+++ b/Projects/DataSource/Sources/DTO/RoutineResponseDTO.swift
@@ -26,13 +26,15 @@ struct RoutineResponseDTO: Decodable {
 
 extension RoutineResponseDTO {
     func toRoutineEntity() -> RoutineEntity {
+        let sortedSubRoutinesDTO = subRoutineSearchResultDto.sorted { $0.sortOrder < $1.sortOrder }
+
         return RoutineEntity(
             routineId: routineId,
             historySeq: historySeq,
             routineName: routineName,
             repeatDay: repeatDay,
             executionTime: executionTime,
-            subRoutineSearchResultDto: subRoutineSearchResultDto.map({ $0.toSubRoutineEntity() }),
+            subRoutineSearchResultDto: sortedSubRoutinesDTO.map({ $0.toSubRoutineEntity() }),
             modifiedYn: modifiedYn,
             routineCompletionId: routineCompletionId,
             completeYn: completeYn,
diff --git a/Projects/DataSource/Sources/DTO/RoutineUpdateDTO.swift b/Projects/DataSource/Sources/DTO/RoutineUpdateDTO.swift
new file mode 100644
index 00000000..52ded8a4
--- /dev/null
+++ b/Projects/DataSource/Sources/DTO/RoutineUpdateDTO.swift
@@ -0,0 +1,14 @@
+//
+//  RoutineUpdateDTO.swift
+//  DataSource
+//
+//  Created by 이동현 on 8/3/25.
+//
+
+struct RoutineUpdateDTO: Codable {
+    let routineId: String
+    let routineName: String
+    let repeatDay: [String]
+    let executionTime: String
+    let subRoutineInfos: [SubRoutineUpdateDTO]
+}
diff --git a/Projects/DataSource/Sources/DTO/SubRoutineUpdateDTO.swift b/Projects/DataSource/Sources/DTO/SubRoutineUpdateDTO.swift
new file mode 100644
index 00000000..52aeddcc
--- /dev/null
+++ b/Projects/DataSource/Sources/DTO/SubRoutineUpdateDTO.swift
@@ -0,0 +1,12 @@
+//
+//  SubRoutineUpdateDTO.swift
+//  DataSource
+//
+//  Created by 이동현 on 8/3/25.
+//
+
+struct SubRoutineUpdateDTO: Codable {
+    let subRoutineId: String?
+    let subRoutineName: String?
+    let sortOrder: Int?
+}
diff --git a/Projects/DataSource/Sources/Endpoint/RoutineEndpoint.swift b/Projects/DataSource/Sources/Endpoint/RoutineEndpoint.swift
index 5896af7c..b6ddcd0b 100644
--- a/Projects/DataSource/Sources/Endpoint/RoutineEndpoint.swift
+++ b/Projects/DataSource/Sources/Endpoint/RoutineEndpoint.swift
@@ -6,7 +6,10 @@
 //
 
 enum RoutineEndpoint {
+    case createRoutine(routine: RoutineCreationDTO)
+    case fetchRoutine(routineId: String)
     case fetchRoutines(startDate: String, endDate: String)
+    case updateRoutine(routine: RoutineUpdateDTO)
 }
 
 extension RoutineEndpoint: Endpoint {
@@ -16,13 +19,21 @@ extension RoutineEndpoint: Endpoint {
 
     var path: String {
         switch self {
-        case .fetchRoutines: baseURL
+        case .fetchRoutine(let routineId):
+            "\(baseURL)/\(routineId)"
+        default:
+            baseURL
         }
     }
     
     var method: HTTPMethod {
         switch self {
-        case .fetchRoutines: .get
+        case .createRoutine:
+                .post
+        case .fetchRoutine, .fetchRoutines:
+                .get
+        case .updateRoutine:
+                .patch
         }
     }
     
@@ -40,11 +51,20 @@ extension RoutineEndpoint: Endpoint {
             return [
                 "startDate": startDate,
                 "endDate": endDate]
+        default:
+            return [:]
         }
     }
     
     var bodyParameters: [String : Any] {
-        return [:]
+        switch self {
+        case .createRoutine(let routine):
+            return routine.dictionary
+        case .updateRoutine(let routine):
+            return routine.dictionary
+        default:
+            return [:]
+        }
     }
     
     var isAuthorized: Bool {
diff --git a/Projects/DataSource/Sources/Repository/RoutineRepository.swift b/Projects/DataSource/Sources/Repository/RoutineRepository.swift
index 46d92e13..eb9320c8 100644
--- a/Projects/DataSource/Sources/Repository/RoutineRepository.swift
+++ b/Projects/DataSource/Sources/Repository/RoutineRepository.swift
@@ -10,6 +10,26 @@ import Domain
 final class RoutineRepository: RoutineRepositoryProtocol {
     private let networkService = NetworkService.shared
 
+    func createRoutine(routineSummary: RoutineSummaryEntity, subRoutineSummaries: [SubRoutineSummaryEntity]) async throws {
+        let subRoutineNames = subRoutineSummaries.compactMap { $0.subRoutineName }
+
+        let routineCreationDTO = RoutineCreationDTO(
+            routineName: routineSummary.routineName,
+            repeatDay: routineSummary.repeatDay.map { $0.rawValue },
+            executionTime: routineSummary.executionTime,
+            subRoutineName: subRoutineNames)
+        let endpoint = RoutineEndpoint.createRoutine(routine: routineCreationDTO)
+
+        _ = try await networkService.request(endpoint: endpoint, type: EmptyResponseDTO.self)
+    }
+    
+    func fetchRoutine(routineId: String) async throws -> RoutineEntity? {
+        let endpoint = RoutineEndpoint.fetchRoutine(routineId: routineId)
+        guard let response = try await networkService.request(endpoint: endpoint, type: RoutineResponseDTO.self) else { return nil }
+        
+        return response.toRoutineEntity()
+    }
+
     func fetchRoutines(from startDate: String, to endDate: String) async throws -> [String: [RoutineEntity]] {
         let endpoint = RoutineEndpoint.fetchRoutines(startDate: startDate, endDate: endDate)
         guard let response = try await networkService.request(endpoint: endpoint, type: RoutineDictionaryDTO.self)
@@ -21,4 +41,25 @@ final class RoutineRepository: RoutineRepositoryProtocol {
         }
         return result
     }
+
+    func updateRoutine(routineSummary: RoutineSummaryEntity, subRoutineSummaries: [SubRoutineSummaryEntity]) async throws {
+        guard let routineId = routineSummary.routineId else { return }
+
+        let subRoutineDTO = subRoutineSummaries.map {
+            SubRoutineUpdateDTO(
+                subRoutineId: $0.subRoutineId,
+                subRoutineName: $0.subRoutineName,
+                sortOrder: $0.sortOrder)
+        }
+
+        let routineUpdateDTO = RoutineUpdateDTO(
+            routineId: routineId,
+            routineName: routineSummary.routineName,
+            repeatDay: routineSummary.repeatDay.map { $0.rawValue },
+            executionTime: routineSummary.executionTime,
+            subRoutineInfos: subRoutineDTO)
+        let endpoint = RoutineEndpoint.updateRoutine(routine: routineUpdateDTO)
+
+        _ = try await networkService.request(endpoint: endpoint, type: EmptyResponseDTO.self)
+    }
 }
diff --git a/Projects/Domain/Sources/Entity/Enum/WeekType.swift b/Projects/Domain/Sources/Entity/Enum/WeekType.swift
new file mode 100644
index 00000000..822bfa68
--- /dev/null
+++ b/Projects/Domain/Sources/Entity/Enum/WeekType.swift
@@ -0,0 +1,16 @@
+//
+//  Week.swift
+//  Domain
+//
+//  Created by 이동현 on 8/3/25.
+//
+
+public enum WeekType: String, CaseIterable {
+    case monday = "MONDAY"
+    case tuesday = "TUESDAY"
+    case wednesday = "WEDNESDAY"
+    case thursday = "THURSDAY"
+    case friday = "FRIDAY"
+    case saturday = "SATURDAY"
+    case sunday = "SUNDAY"
+}
diff --git a/Projects/Domain/Sources/Entity/RoutineEntity.swift b/Projects/Domain/Sources/Entity/RoutineEntity.swift
index 6b068df5..ceb7d8e5 100644
--- a/Projects/Domain/Sources/Entity/RoutineEntity.swift
+++ b/Projects/Domain/Sources/Entity/RoutineEntity.swift
@@ -6,10 +6,10 @@
 //
 
 public struct RoutineEntity {
-    public let routineId: String
+    public let routineId: String?
     public let historySeq: Int
     public let routineName: String
-    public let repeatDay: [String]
+    public let repeatDay: [WeekType]
     public let executionTime: String
     public let subRoutineSearchResultDto: [SubRoutineEntity]
     public let modifiedYn: Bool
@@ -18,7 +18,7 @@ public struct RoutineEntity {
     public let routineType: String
 
     public init(
-        routineId: String,
+        routineId: String?,
         historySeq: Int,
         routineName: String,
         repeatDay: [String]?,
@@ -29,10 +29,12 @@ public struct RoutineEntity {
         completeYn: Bool,
         routineType: String
     ) {
+        let weekType: [WeekType] = repeatDay?.compactMap(WeekType.init(rawValue:)) ?? []
+
         self.routineId = routineId
         self.historySeq = historySeq
         self.routineName = routineName
-        self.repeatDay = repeatDay ?? []
+        self.repeatDay = weekType
         self.executionTime = executionTime
         self.subRoutineSearchResultDto = subRoutineSearchResultDto
         self.modifiedYn = modifiedYn
diff --git a/Projects/Domain/Sources/Entity/RoutineSummaryEntity.swift b/Projects/Domain/Sources/Entity/RoutineSummaryEntity.swift
new file mode 100644
index 00000000..616f408b
--- /dev/null
+++ b/Projects/Domain/Sources/Entity/RoutineSummaryEntity.swift
@@ -0,0 +1,27 @@
+//
+//  RoutineSummaryEntity.swift
+//  Domain
+//
+//  Created by 이동현 on 8/3/25.
+//
+
+public struct RoutineSummaryEntity {
+    public let routineId: String?
+    public let routineName: String
+    public let repeatDay: [WeekType]
+    public let executionTime: String
+
+    public init(
+        routineId: String?,
+        routineName: String,
+        repeatDay: [String]?,
+        executionTime: String
+    ) {
+        let weekType: [WeekType] = repeatDay?.compactMap(WeekType.init(rawValue:)) ?? []
+
+        self.routineId = routineId
+        self.routineName = routineName
+        self.repeatDay = weekType
+        self.executionTime = executionTime
+    }
+}
diff --git a/Projects/Domain/Sources/Entity/SubRoutineEntity.swift b/Projects/Domain/Sources/Entity/SubRoutineEntity.swift
index 5b423d4b..091bf49e 100644
--- a/Projects/Domain/Sources/Entity/SubRoutineEntity.swift
+++ b/Projects/Domain/Sources/Entity/SubRoutineEntity.swift
@@ -6,7 +6,7 @@
 //
 
 public struct SubRoutineEntity: Decodable {
-    public let subRoutineId: String
+    public let subRoutineId: String?
     public let historySeq: Int
     public let subRoutineName: String
     public let modifiedYn: Bool
diff --git a/Projects/Domain/Sources/Entity/SubRoutineSummaryEntity.swift b/Projects/Domain/Sources/Entity/SubRoutineSummaryEntity.swift
new file mode 100644
index 00000000..100d6ba5
--- /dev/null
+++ b/Projects/Domain/Sources/Entity/SubRoutineSummaryEntity.swift
@@ -0,0 +1,22 @@
+//
+//  SubRoutineSummaryEntity.swift
+//  Domain
+//
+//  Created by 이동현 on 8/3/25.
+//
+
+public struct SubRoutineSummaryEntity: Decodable, Hashable {
+    public let subRoutineId: String?
+    public let subRoutineName: String?
+    public let sortOrder: Int?
+
+    public init(
+        subRoutineId: String?,
+        subRoutineName: String?,
+        sortOrder: Int?
+    ) {
+        self.subRoutineId = subRoutineId
+        self.subRoutineName = subRoutineName
+        self.sortOrder = sortOrder
+    }
+}
diff --git a/Projects/Domain/Sources/Entity/Untitled.swift b/Projects/Domain/Sources/Entity/Untitled.swift
new file mode 100644
index 00000000..b0e96cdd
--- /dev/null
+++ b/Projects/Domain/Sources/Entity/Untitled.swift
@@ -0,0 +1,7 @@
+//
+//  Untitled.swift
+//  Domain
+//
+//  Created by 이동현 on 8/3/25.
+//
+
diff --git a/Projects/Domain/Sources/Protocol/Repository/RoutineRepositoryProtocol.swift b/Projects/Domain/Sources/Protocol/Repository/RoutineRepositoryProtocol.swift
index ee13d44b..45562454 100644
--- a/Projects/Domain/Sources/Protocol/Repository/RoutineRepositoryProtocol.swift
+++ b/Projects/Domain/Sources/Protocol/Repository/RoutineRepositoryProtocol.swift
@@ -7,9 +7,27 @@
 
 // 루틴 관련 로직(조회, 완료, 등록, 삭제 등)을 수행하는 Repository
 public protocol RoutineRepositoryProtocol {
-    /// 루틴을 조회합니다. (기간)
+    /// 루틴을 생성합니다.
+    /// - Parameters:
+    ///   - routineSummary: 루틴 요약 정보
+    ///   - subRoutineSummaries: 서브 루틴 요약 정보 배열
+    func createRoutine(routineSummary: RoutineSummaryEntity, subRoutineSummaries: [SubRoutineSummaryEntity]) async throws
+
+    /// 루틴을 조회합니다.
+    /// - Parameter routineId: 조회할 루틴 id
+    /// - Returns: 조회된 루틴
+    func fetchRoutine(routineId: String) async throws -> RoutineEntity?
+
+    /// 루틴 목록을 조회합니다. (기간)
     /// - Parameters:
     ///   - startDate: 조회 시작 날짜
     ///   - endDate: 조회 종료 날짜
     func fetchRoutines(from startDate: String, to endDate: String) async throws -> [String: [RoutineEntity]]
+
+
+    /// 루틴을 수정합니다.
+    /// - Parameters:
+    ///   - routineSummary: 루틴 요약 정보
+    ///   - subRoutineSummaries: 서브 루틴 요약 정보 배열
+    func updateRoutine(routineSummary: RoutineSummaryEntity, subRoutineSummaries: [SubRoutineSummaryEntity]) async throws
 }
diff --git a/Projects/Domain/Sources/Protocol/UseCase/RoutineUseCaseProtocol.swift b/Projects/Domain/Sources/Protocol/UseCase/RoutineUseCaseProtocol.swift
index bb129a62..6d3e4b9a 100644
--- a/Projects/Domain/Sources/Protocol/UseCase/RoutineUseCaseProtocol.swift
+++ b/Projects/Domain/Sources/Protocol/UseCase/RoutineUseCaseProtocol.swift
@@ -8,5 +8,13 @@
 import Foundation
 
 public protocol RoutineUseCaseProtocol {
+    func fetchRoutine(routineId: String) async throws -> RoutineEntity?
+
     func fetchRoutines(startDate: Date, endDate: Date) async throws -> [String: [RoutineEntity]]
+
+    func saveRoutine(
+        routineSummary: RoutineSummaryEntity,
+        subRoutineSummaries: [SubRoutineSummaryEntity],
+        deletedSubRoutineSummaries: [SubRoutineSummaryEntity]
+    ) async throws
 }
diff --git a/Projects/Domain/Sources/UseCase/Routine/RoutineUseCase.swift b/Projects/Domain/Sources/UseCase/Routine/RoutineUseCase.swift
index 58ae3e52..6496177e 100644
--- a/Projects/Domain/Sources/UseCase/Routine/RoutineUseCase.swift
+++ b/Projects/Domain/Sources/UseCase/Routine/RoutineUseCase.swift
@@ -15,11 +15,59 @@ public final class RoutineUseCase: RoutineUseCaseProtocol {
         self.routineRepository = routineRepository
     }
 
+    public func fetchRoutine(routineId: String) async throws -> RoutineEntity? {
+        let routineEnity = try await routineRepository.fetchRoutine(routineId: routineId)
+        return routineEnity
+    }
+
     public func fetchRoutines(startDate: Date, endDate: Date) async throws -> [String: [RoutineEntity]] {
         let start = startDate.convertToString(dateType: .yearMonthDate)
         let end = endDate.convertToString(dateType: .yearMonthDate)
 
-        var routineEntities = try await routineRepository.fetchRoutines(from: start, to: end)
+        let routineEntities = try await routineRepository.fetchRoutines(from: start, to: end)
         return routineEntities
     }
+
+    public func saveRoutine(
+        routineSummary: RoutineSummaryEntity,
+        subRoutineSummaries: [SubRoutineSummaryEntity],
+        deletedSubRoutineSummaries: [SubRoutineSummaryEntity]
+    ) async throws {
+        if routineSummary.routineId == nil { // 루틴 아이디가 있으면 수정, 없으면 생성
+            try await createRoutine(routineSummary: routineSummary, subRoutinesSummaries: subRoutineSummaries)
+        } else {
+            try await updateRoutine(
+                routineSummary: routineSummary,
+                subRoutineSummaries: subRoutineSummaries,
+                deletedSubRoutineSummaries: deletedSubRoutineSummaries)
+        }
+    }
+
+    private func createRoutine(routineSummary: RoutineSummaryEntity, subRoutinesSummaries: [SubRoutineSummaryEntity]) async throws {
+        try await routineRepository.createRoutine(routineSummary: routineSummary, subRoutineSummaries: subRoutinesSummaries)
+    }
+
+    private func updateRoutine(
+        routineSummary: RoutineSummaryEntity,
+        subRoutineSummaries: [SubRoutineSummaryEntity],
+        deletedSubRoutineSummaries: [SubRoutineSummaryEntity]
+    ) async throws {
+        let updatedSubRoutines = subRoutineSummaries
+            .enumerated()
+            .map {
+                SubRoutineSummaryEntity(
+                    subRoutineId: $1.subRoutineId,
+                    subRoutineName: $1.subRoutineName,
+                    sortOrder: $0 + 1)
+            }
+        let deletedSubRoutines = deletedSubRoutineSummaries.map {
+            SubRoutineSummaryEntity(
+                subRoutineId: $0.subRoutineId,
+                subRoutineName: nil,
+                sortOrder: nil)
+        }
+        let finalSubRoutines = updatedSubRoutines + deletedSubRoutines
+
+        try await routineRepository.updateRoutine(routineSummary: routineSummary, subRoutineSummaries: finalSubRoutines)
+    }
 }
diff --git a/Projects/Presentation/Sources/Common/PresentationDependencyAssembler.swift b/Projects/Presentation/Sources/Common/PresentationDependencyAssembler.swift
index 4f69ce3e..0cd688b0 100644
--- a/Projects/Presentation/Sources/Common/PresentationDependencyAssembler.swift
+++ b/Projects/Presentation/Sources/Common/PresentationDependencyAssembler.swift
@@ -66,8 +66,11 @@ public struct PresentationDependencyAssembler: DependencyAssemblerProtocol {
             return EmotionRegisterViewModel(emotionUseCase: emotionUseCase)
         }
 
-        DIContainer.shared.register(type: RoutineCreationViewModel.self) { _ in
-            return RoutineCreationViewModel()
+        DIContainer.shared.register(type: RoutineCreationViewModel.self) { container in
+            guard let routineUseCase = container.resolve(type: RoutineUseCaseProtocol.self)
+            else { fatalError("routineUseCase 의존성이 등록되지 않았습니다.") }
+
+            return RoutineCreationViewModel(routineUseCase: routineUseCase)
         }
 
         DIContainer.shared.register(type: ResultRecommendedRoutineViewModel.self) { container in
diff --git a/Projects/Presentation/Sources/Home/Model/MainRoutine.swift b/Projects/Presentation/Sources/Home/Model/MainRoutine.swift
index bfaec215..77722cc2 100644
--- a/Projects/Presentation/Sources/Home/Model/MainRoutine.swift
+++ b/Projects/Presentation/Sources/Home/Model/MainRoutine.swift
@@ -18,13 +18,19 @@ struct MainRoutine {
 }
 
 extension RoutineEntity {
-    func toMainRoutine() -> MainRoutine {
+    func toMainRoutine() -> MainRoutine? {
+        guard let routineId else { return nil }
+
+        let subRoutines = subRoutineSearchResultDto.compactMap { $0.toSubRoutine() }
+        let isAllConverted = subRoutines.count == subRoutineSearchResultDto.count
+        guard isAllConverted else { return nil }
+
         return MainRoutine(
             id: routineId,
             title: routineName,
             isDone: completeYn,
             startTime: Date.convertToDate(from: executionTime, dateType: .time) ?? Date(),
-            repeatDay: repeatDay.compactMap({ Week(rawValue: $0) }),
-            subRoutines: subRoutineSearchResultDto.map({ $0.toSubRoutine() }))
+            repeatDay: repeatDay.compactMap({ Week(rawValue: $0.rawValue) }),
+            subRoutines: subRoutines)
     }
 }
diff --git a/Projects/Presentation/Sources/Home/Model/SubRoutine.swift b/Projects/Presentation/Sources/Home/Model/SubRoutine.swift
index e90867c3..0800b392 100644
--- a/Projects/Presentation/Sources/Home/Model/SubRoutine.swift
+++ b/Projects/Presentation/Sources/Home/Model/SubRoutine.swift
@@ -15,7 +15,9 @@ struct SubRoutine: Hashable {
 }
 
 extension SubRoutineEntity {
-    func toSubRoutine() -> SubRoutine {
+    func toSubRoutine() -> SubRoutine? {
+        guard let subRoutineId else { return nil }
+
         return SubRoutine(
             id: subRoutineId,
             title: subRoutineName,
diff --git a/Projects/Presentation/Sources/Home/View/HomeView.swift b/Projects/Presentation/Sources/Home/View/HomeView.swift
index 5560b9dc..9b68b274 100644
--- a/Projects/Presentation/Sources/Home/View/HomeView.swift
+++ b/Projects/Presentation/Sources/Home/View/HomeView.swift
@@ -529,7 +529,7 @@ extension HomeView: RoutineDetailViewDelegate {
         guard let routineCreationViewModel = DIContainer.shared.resolve(type: RoutineCreationViewModel.self) else {
             fatalError("routineCreationViewModel 의존성이 등록되지 않았습니다.")
         }
-        let routineCreationView = RoutineCreationView(viewModel: routineCreationViewModel)
+        let routineCreationView = RoutineCreationView(viewModel: routineCreationViewModel, routineId: routine.id)
         routineCreationView.hidesBottomBarWhenPushed = true
         self.navigationController?.pushViewController(routineCreationView, animated: true)
     }
diff --git a/Projects/Presentation/Sources/Home/ViewModel/HomeViewModel.swift b/Projects/Presentation/Sources/Home/ViewModel/HomeViewModel.swift
index 652212e7..fc3542ac 100644
--- a/Projects/Presentation/Sources/Home/ViewModel/HomeViewModel.swift
+++ b/Projects/Presentation/Sources/Home/ViewModel/HomeViewModel.swift
@@ -98,7 +98,7 @@ final class HomeViewModel: ViewModel {
             do {
                 let entities = try await routineUseCase.fetchRoutines(startDate: startDate, endDate: endDate)
                 for (date, routineEntities) in entities {
-                    routines[date] = routineEntities.map({ $0.toMainRoutine() })
+                    routines[date] = routineEntities.compactMap({ $0.toMainRoutine() })
                 }
                 fetchRoutineResultSubject.send(true)
             } catch {
diff --git a/Projects/Presentation/Sources/RoutineCreation/View/RoutineCreationView.swift b/Projects/Presentation/Sources/RoutineCreation/View/RoutineCreationView.swift
index 7e7ea106..83f2146e 100644
--- a/Projects/Presentation/Sources/RoutineCreation/View/RoutineCreationView.swift
+++ b/Projects/Presentation/Sources/RoutineCreation/View/RoutineCreationView.swift
@@ -77,26 +77,30 @@ final class RoutineCreationView: BaseViewController<RoutineCreationViewModel> {
 
     private let registerButton = UIButton()
 
+    private let navigationTitle: String
+    private let registerButtonTitle: String
     private var repeatRoutineTitleTopConstraint: Constraint?
     private var startTimeTitleTopConstraint: Constraint?
 
     private var cancellables = Set<AnyCancellable>()
 
-    override init(viewModel: RoutineCreationViewModel) {
+    init(viewModel: RoutineCreationViewModel, routineId: String? = nil) {
+        navigationTitle = routineId == nil ? "루틴 등록" : "루틴 수정"
+        registerButtonTitle = routineId == nil ? "등록하기" : "수정하기"
+
         super.init(viewModel: viewModel)
+        if let routineId {
+            viewModel.action(input: .fetchRoutine(id: routineId))
+        }
     }
     
     required init?(coder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
-    
-    override func viewDidLoad() {
-        super.viewDidLoad()
-    }
 
     override func viewWillAppear(_ animated: Bool) {
         super.viewWillAppear(animated)
-        configureNavigationBar(navigationStyle: .withBackButton(title: "루틴 등록"))
+        configureNavigationBar(navigationStyle: .withBackButton(title: navigationTitle))
     }
 
     override func configureAttribute() {
@@ -171,7 +175,7 @@ final class RoutineCreationView: BaseViewController<RoutineCreationViewModel> {
 
         registerButton.layer.cornerRadius = 12
         registerButton.layer.masksToBounds = true
-        registerButton.setTitle("등록하기", for: .normal)
+        registerButton.setTitle(registerButtonTitle, for: .normal)
         registerButton.isEnabled = false
         registerButton.titleLabel?.font = BitnagilFont.init(style: .body1, weight: .semiBold).font
     }
@@ -519,6 +523,12 @@ final class RoutineCreationView: BaseViewController<RoutineCreationViewModel> {
                 self?.presentCustomBottomSheet(contentViewController: datePickerView, maxHeight: Layout.datePickerBottomSheetHeight)
             },
             for: .touchUpInside)
+
+        registerButton.addAction(
+            UIAction { [weak self] _ in
+                self?.viewModel.action(input: .registerRoutine)
+            },
+            for: .touchUpInside)
     }
 
     private func configureSubroutineStackView() {
diff --git a/Projects/Presentation/Sources/RoutineCreation/ViewModel/RoutineCreationViewModel.swift b/Projects/Presentation/Sources/RoutineCreation/ViewModel/RoutineCreationViewModel.swift
index b14c377b..49b86a61 100644
--- a/Projects/Presentation/Sources/RoutineCreation/ViewModel/RoutineCreationViewModel.swift
+++ b/Projects/Presentation/Sources/RoutineCreation/ViewModel/RoutineCreationViewModel.swift
@@ -4,7 +4,9 @@
 //
 //  Created by 이동현 on 7/20/25.
 //
+
 import Combine
+import Domain
 import Foundation
 
 final class RoutineCreationViewModel: ViewModel {
@@ -38,6 +40,7 @@ final class RoutineCreationViewModel: ViewModel {
     }
 
     enum Input {
+        case fetchRoutine(id: String)
         case configureName(name: String)
         case addSubRoutine
         case deleteSubRoutine(index: Int)
@@ -60,16 +63,23 @@ final class RoutineCreationViewModel: ViewModel {
 
     private(set) var output: Output
     private let nameSubject = CurrentValueSubject<String?, Never>("")
-    private let subRoutinesSubject = CurrentValueSubject<[String], Never>([])
+    private let subRoutinesSubject = CurrentValueSubject<[SubRoutineSummaryEntity], Never>([])
     private let repeatTypeSubject = CurrentValueSubject<RepeatType?, Never>(nil)
     private let weekDaySubject = CurrentValueSubject<Set<Week>, Never>([])
     private let executionTimeSubject = CurrentValueSubject<ExecutionType, Never>(.none)
     private let checkRoutinePublisher = PassthroughSubject<Bool, Never>()
+    private let routineUseCase: RoutineUseCaseProtocol
+    private var deletedSubroutines = Set<SubRoutineSummaryEntity>()
+    private var routineId: String?
+
+    init(routineUseCase: RoutineUseCaseProtocol) {
+        self.routineUseCase = routineUseCase
 
-    init() {
         output = Output(
             namePublisher: nameSubject.eraseToAnyPublisher(),
-            subRoutinesPublisher: subRoutinesSubject.eraseToAnyPublisher(),
+            subRoutinesPublisher: subRoutinesSubject
+                .map { $0.compactMap { $0.subRoutineName } }
+                .eraseToAnyPublisher(),
             repeatTypePublisher: repeatTypeSubject.eraseToAnyPublisher(),
             weekDayPublisher: weekDaySubject.eraseToAnyPublisher(),
             executionTimePublisher: executionTimeSubject
@@ -80,6 +90,8 @@ final class RoutineCreationViewModel: ViewModel {
 
     func action(input: Input) {
         switch input {
+        case .fetchRoutine(let id):
+            fetchRoutine(id: id)
         case .configureName(let name):
             configureName(name: name)
         case .addSubRoutine:
@@ -89,7 +101,7 @@ final class RoutineCreationViewModel: ViewModel {
         case .configureSubRoutine(let name, let index):
             configureSubroutine(name: name, index: index)
         case .configureRepeatType(let type):
-            configureRepeatType(type: type)
+            configureRepeatType(selectedType: type)
         case .toggleRepeatDay(let weekDay):
             configureWeekDay(weekDay: weekDay)
         case .toggleRepeatAllDay:
@@ -103,6 +115,43 @@ final class RoutineCreationViewModel: ViewModel {
         updateIsRoutineValid()
     }
 
+    private func fetchRoutine(id: String) {
+        Task {
+            do {
+                // TODO: - routine fetch 실패 시 처리 방안 필요 (기획과 논의~)
+                guard let routine = try await routineUseCase.fetchRoutine(routineId: id) else { return }
+
+                let subRoutines = routine.subRoutineSearchResultDto.map {
+                    SubRoutineSummaryEntity(
+                        subRoutineId: $0.subRoutineId,
+                        subRoutineName: $0.subRoutineName,
+                        sortOrder: $0.sortOrder)
+                }
+                let weekDay = routine.repeatDay.compactMap { Week(rawValue: $0.rawValue) }
+                let repeatType: RepeatType = weekDay.count == Week.allCases.count ? .daily : .week
+                let executionType: ExecutionType
+
+                if routine.executionTime == "00:00:00" {
+                    executionType = .allDay
+                } else {
+                    let time = Date.convertToDate(from: routine.executionTime, dateType: .amPmTimeShort)
+                    executionType = .time(startAt: time ?? Date())
+                }
+
+                nameSubject.send(routine.routineName)
+                subRoutinesSubject.send(subRoutines)
+                weekDaySubject.send(Set(weekDay))
+                repeatTypeSubject.send(repeatType)
+                executionTimeSubject.send(executionType)
+                routineId = id
+
+                updateIsRoutineValid()
+            } catch {
+                // TODO: - 요기도 마찬가지 (ViewModel 공통 todo)
+            }
+        }
+    }
+
     private func configureName(name: String) {
         nameSubject.send(name)
     }
@@ -111,7 +160,12 @@ final class RoutineCreationViewModel: ViewModel {
         var subRoutines = subRoutinesSubject.value
         guard subRoutines.count <= 3 else { return }
 
-        subRoutines.append("")
+        let newSubRoutine = SubRoutineSummaryEntity(
+            subRoutineId: nil,
+            subRoutineName: "",
+            sortOrder: subRoutines.count + 1)
+
+        subRoutines.append(newSubRoutine)
         subRoutinesSubject.send(subRoutines)
     }
 
@@ -122,6 +176,12 @@ final class RoutineCreationViewModel: ViewModel {
             index < subRoutines.count
         else { return }
 
+        let targetSubRoutine = subRoutines[index]
+
+        if targetSubRoutine.subRoutineId != nil {
+            deletedSubroutines.insert(targetSubRoutine)
+        }
+
         subRoutines.remove(at: index)
         subRoutinesSubject.send(subRoutines)
     }
@@ -133,21 +193,29 @@ final class RoutineCreationViewModel: ViewModel {
             index < subRoutines.count
         else { return }
 
-        subRoutines[index] = name
+        let originalSubRoutine = subRoutines[index]
+        let newSubRoutine = SubRoutineSummaryEntity(
+            subRoutineId: originalSubRoutine.subRoutineId,
+            subRoutineName: name,
+            sortOrder: originalSubRoutine.sortOrder)
+        subRoutines[index] = newSubRoutine
+
         subRoutinesSubject.send(subRoutines)
     }
 
-    private func configureRepeatType(type: RepeatType) {
-        var repeatType = repeatTypeSubject.value
-
-        repeatType = repeatType == type
-            ? nil
-            : type
+    private func configureRepeatType(selectedType: RepeatType) {
+        let repeatType = repeatTypeSubject.value
 
-        if repeatType != .week {
-            weekDaySubject.send([])
+        switch selectedType {
+        case .daily:
+            weekDaySubject.send(Set(Week.allCases))
+        case .week:
+            if repeatType == .daily {
+                weekDaySubject.send([])
+            }
         }
-        repeatTypeSubject.send(repeatType)
+
+        repeatTypeSubject.send(selectedType)
     }
 
     private func configureWeekDay(weekDay: Week) {
@@ -178,7 +246,12 @@ final class RoutineCreationViewModel: ViewModel {
         guard
             let name = nameSubject.value,
             !name.isEmpty,
-            executionTimeSubject.value != .none
+            executionTimeSubject.value != .none,
+            weekDaySubject.value.count > 0,
+            subRoutinesSubject
+                .value
+                .map({$0.subRoutineName})
+                .allSatisfy({$0?.isEmpty == false })
         else {
             checkRoutinePublisher.send(false)
             return
@@ -188,6 +261,37 @@ final class RoutineCreationViewModel: ViewModel {
     }
 
     private func registerRoutine() {
-        // API 호출
+        Task {
+            do {
+                let repeatDay = weekDaySubject
+                    .value
+                    .sorted(by: { $0.id < $1.id })
+                    .map { $0.rawValue }
+
+                let executionTime: String
+
+                switch executionTimeSubject.value {
+                case .time(let startAt):
+                    executionTime = startAt.convertToString(dateType: .time)
+                case .allDay:
+                    executionTime = "00:00:00"
+                case .none:
+                    return
+                }
+
+                let routineSummary = RoutineSummaryEntity(
+                    routineId: routineId,
+                    routineName: nameSubject.value ?? "",
+                    repeatDay: repeatDay,
+                    executionTime: executionTime)
+
+                try await routineUseCase.saveRoutine(
+                    routineSummary: routineSummary,
+                    subRoutineSummaries: subRoutinesSubject.value,
+                    deletedSubRoutineSummaries: Array(deletedSubroutines))
+            } catch {
+
+            }
+        }
     }
 }