diff --git a/pyproject.toml b/pyproject.toml
index 5c6c855485e..91d93136d1f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -69,7 +69,7 @@ dev = [
     "aws-sam-cli[pre-dev]",
     "coverage==7.14.0",
     "pytest-cov==7.1.0",
-    "mypy==1.19.1",
+    "mypy==2.1.0",
     "types-pywin32==311.0.0.20260508",
     "types-PyYAML==6.0.12.20250915",
     "types-chevron==0.14.2.20250103",
diff --git a/samcli/lib/sync/sync_flow.py b/samcli/lib/sync/sync_flow.py
index b7dc94ac3b7..1f5fec38ade 100644
--- a/samcli/lib/sync/sync_flow.py
+++ b/samcli/lib/sync/sync_flow.py
@@ -347,7 +347,7 @@ def __hash__(self) -> int:
     def __eq__(self, o: object) -> bool:
         if type(o) is not type(self):
             return False
-        return cast(bool, self._equality_keys() == cast(SyncFlow, o)._equality_keys())
+        return cast(bool, self._equality_keys() == o._equality_keys())
 
     @property
     def log_name(self) -> str:
diff --git a/samcli/lib/telemetry/metric.py b/samcli/lib/telemetry/metric.py
index f573ddc4467..afead773e18 100644
--- a/samcli/lib/telemetry/metric.py
+++ b/samcli/lib/telemetry/metric.py
@@ -42,7 +42,7 @@
 No side effect will result in this as it is write-only for code outside of telemetry.
 Decorators should be used to minimize logic involving telemetry.
 """
-_METRICS = dict()
+_METRICS: Dict[str, "Metric"] = dict()
 
 # Global container socket and runtime information for telemetry
 # This persists across context boundaries to ensure accurate telemetry reporting
diff --git a/samcli/lib/utils/resource_trigger.py b/samcli/lib/utils/resource_trigger.py
index 8a8774fa8ab..194579837b7 100644
--- a/samcli/lib/utils/resource_trigger.py
+++ b/samcli/lib/utils/resource_trigger.py
@@ -386,7 +386,7 @@ def _get_definition_file(self) -> str:
         definition_file = self._resource.get("Properties", {}).get(property_name)
         if not definition_file or not isinstance(definition_file, str):
             raise MissingLocalDefinition(self._resource_identifier, property_name)
-        return cast(str, definition_file)
+        return definition_file
 
     def _validator_wrapper(self, event: Optional[FileSystemEvent] = None):
         """Wrapper for callback that only executes if the definition is valid and non-trivial changes are detected.
diff --git a/samcli/local/apigw/authorizers/lambda_authorizer.py b/samcli/local/apigw/authorizers/lambda_authorizer.py
index eb4860b9754..21450ec2a4a 100644
--- a/samcli/local/apigw/authorizers/lambda_authorizer.py
+++ b/samcli/local/apigw/authorizers/lambda_authorizer.py
@@ -6,7 +6,7 @@
 from abc import ABC, abstractmethod
 from dataclasses import dataclass
 from json import JSONDecodeError, loads
-from typing import Any, Dict, List, Optional, Tuple, Type, Union, cast
+from typing import Any, Dict, List, Optional, Tuple, Type, Union
 from urllib.parse import parse_qsl
 
 from samcli.commands.local.lib.validators.identity_source_validator import IdentitySourceValidator
@@ -417,7 +417,7 @@ def _validate_simple_response(self, response: dict) -> bool:
                 f"Authorizer {self.authorizer_name} is missing or contains an invalid " f"{_SIMPLE_RESPONSE_IS_AUTH}"
             )
 
-        return cast(bool, is_authorized)
+        return is_authorized
 
     def get_context(self, response: Union[str, bytes]) -> Dict[str, Any]:
         """