diff --git a/.github/workflows/benchmark-tags.yml b/.github/workflows/benchmark-tags.yml
index 45bdde09133..486a1b0840d 100644
--- a/.github/workflows/benchmark-tags.yml
+++ b/.github/workflows/benchmark-tags.yml
@@ -31,7 +31,7 @@ jobs:
         uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
 
       - name: Set up gradle
         uses: gradle/actions/setup-gradle@4d9f0ba0025fe599b4ebab900eb7f3a1d93ef4c2 # v5.0.0
diff --git a/.github/workflows/benchmark.yml b/.github/workflows/benchmark.yml
index 83aed52b814..a95613ccdd7 100644
--- a/.github/workflows/benchmark.yml
+++ b/.github/workflows/benchmark.yml
@@ -33,7 +33,7 @@ jobs:
         uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
 
       - name: Set up gradle
         uses: gradle/actions/setup-gradle@4d9f0ba0025fe599b4ebab900eb7f3a1d93ef4c2 # v5.0.0
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f41d2f08a79..ca83c4337d7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -66,7 +66,7 @@ jobs:
         uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
 
       - name: Set up gradle
         uses: gradle/actions/setup-gradle@4d9f0ba0025fe599b4ebab900eb7f3a1d93ef4c2 # v5.0.0
@@ -143,7 +143,7 @@ jobs:
         uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
 
       - name: Set up gradle
         uses: gradle/actions/setup-gradle@4d9f0ba0025fe599b4ebab900eb7f3a1d93ef4c2 # v5.0.0
diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index f613bcc9b34..36030a3155f 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -33,12 +33,12 @@ jobs:
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
 
-      - name: Set up Java 17
+      - name: Set up Java 21
         if: matrix.language == 'java'
         uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
 
       - name: Set up gradle
         if: matrix.language == 'java'
diff --git a/.github/workflows/javadoc-crawler.yml b/.github/workflows/javadoc-crawler.yml
index 714e148a9b5..415a6c7e400 100644
--- a/.github/workflows/javadoc-crawler.yml
+++ b/.github/workflows/javadoc-crawler.yml
@@ -17,7 +17,7 @@ jobs:
       - uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
 
       - name: Set up gradle
         uses: gradle/actions/setup-gradle@4d9f0ba0025fe599b4ebab900eb7f3a1d93ef4c2 # v5.0.0
diff --git a/.github/workflows/owasp-dependency-check-daily.yml b/.github/workflows/owasp-dependency-check-daily.yml
index 1b7ec72adab..5dbe5c3d06d 100644
--- a/.github/workflows/owasp-dependency-check-daily.yml
+++ b/.github/workflows/owasp-dependency-check-daily.yml
@@ -19,7 +19,7 @@ jobs:
       - uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
 
       - name: Set up gradle
         uses: gradle/actions/setup-gradle@4d9f0ba0025fe599b4ebab900eb7f3a1d93ef4c2 # v5.0.0
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 10fdb23d3eb..165a9b06704 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -25,7 +25,7 @@ jobs:
       - uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
 
       - name: Set up gradle
         uses: gradle/actions/setup-gradle@4d9f0ba0025fe599b4ebab900eb7f3a1d93ef4c2 # v5.0.0
@@ -183,7 +183,7 @@ jobs:
         uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
         with:
           distribution: temurin
-          java-version: 17
+          java-version: 21
 
       - name: Set up Gradle
         uses: gradle/actions/setup-gradle@4d9f0ba0025fe599b4ebab900eb7f3a1d93ef4c2 # v5.0.0
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 5c02e405c0d..9cb55cf8a37 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -16,7 +16,7 @@ automatic check once you submit a PR, but you can also sign it after opening you
 
 ## Requirements
 
-Java 17 or higher is required to build the projects in this repository. The built artifacts can be
+Java 21 or higher is required to build the projects in this repository. The built artifacts can be
 used on Java 8 or higher.
 
 ## Building opentelemetry-java
diff --git a/buildSrc/build.gradle.kts b/buildSrc/build.gradle.kts
index c7486897383..d992f8d17a1 100644
--- a/buildSrc/build.gradle.kts
+++ b/buildSrc/build.gradle.kts
@@ -5,23 +5,6 @@ plugins {
   id("com.diffplug.spotless") version "8.0.0"
 }
 
-if (!hasLauncherForJavaVersion(17)) {
-  throw GradleException(
-    "JDK 17 is required to build and gradle was unable to detect it on the system.  " +
-        "Please install it and see https://docs.gradle.org/current/userguide/toolchains.html#sec:auto_detection " +
-        "for details on how gradle detects java toolchains."
-  )
-}
-
-fun hasLauncherForJavaVersion(version: Int): Boolean {
-  return try {
-    javaToolchains.launcherFor { languageVersion = JavaLanguageVersion.of(version) }.get()
-    true
-  } catch (e: Exception) {
-    false
-  }
-}
-
 spotless {
   kotlinGradle {
     ktlint().editorConfigOverride(mapOf(
@@ -68,11 +51,3 @@ dependencies {
   implementation("org.owasp:dependency-check-gradle:12.1.8")
   implementation("ru.vyarus:gradle-animalsniffer-plugin:2.0.1")
 }
-
-// We can't apply conventions to this build so include important ones such as the Java compilation
-// target.
-java {
-  toolchain {
-    languageVersion.set(JavaLanguageVersion.of(17))
-  }
-}
diff --git a/buildSrc/src/main/kotlin/otel.java-conventions.gradle.kts b/buildSrc/src/main/kotlin/otel.java-conventions.gradle.kts
index d4216c31d2a..72cf605ab9c 100644
--- a/buildSrc/src/main/kotlin/otel.java-conventions.gradle.kts
+++ b/buildSrc/src/main/kotlin/otel.java-conventions.gradle.kts
@@ -33,7 +33,7 @@ tasks.withType<AbstractArchiveTask>().configureEach {
 
 java {
   toolchain {
-    languageVersion.set(JavaLanguageVersion.of(17))
+    languageVersion.set(JavaLanguageVersion.of(21))
   }
 
   withJavadocJar()
@@ -88,6 +88,8 @@ tasks {
             "-Xlint:-processing",
             // We suppress the "options" warning because it prevents compilation on modern JDKs
             "-Xlint:-options",
+            "-Xlint:-serial",
+            "-Xlint:-this-escape",
             // Fail build on any warning
             "-Werror",
           ),
diff --git a/settings.gradle.kts b/settings.gradle.kts
index b8cce279c90..cb59909198b 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -6,12 +6,13 @@ pluginManagement {
     id("org.jsonschema2pojo") version "1.2.2"
     id("io.github.gradle-nexus.publish-plugin") version "2.0.0"
     id("org.graalvm.buildtools.native") version "0.10.6"
+    id("org.gradle.toolchains.foojay-resolver-convention") version "1.0.0"
   }
 }
 
 plugins {
-  id("org.gradle.toolchains.foojay-resolver-convention") version "1.0.0"
   id("com.gradle.develocity")
+  id("org.gradle.toolchains.foojay-resolver-convention")
 }
 
 dependencyResolutionManagement {