diff --git a/.github/workflows/integ-tests-with-security.yml b/.github/workflows/integ-tests-with-security.yml
index 8ca5a5c1d5..77985193cb 100644
--- a/.github/workflows/integ-tests-with-security.yml
+++ b/.github/workflows/integ-tests-with-security.yml
@@ -20,7 +20,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        java: [ 11, 17, 21 ]
+        java: [21]
 
     runs-on: ubuntu-latest
     container:
@@ -60,7 +60,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ windows-latest ]
-        java: [ 11, 17, 21 ]
+        java: [21]
 
     runs-on: ${{ matrix.os }}
 
diff --git a/.github/workflows/maven-publish.yml b/.github/workflows/maven-publish.yml
index 8adf7ae52c..0dd07404bb 100644
--- a/.github/workflows/maven-publish.yml
+++ b/.github/workflows/maven-publish.yml
@@ -23,7 +23,7 @@ jobs:
       - uses: actions/setup-java@v3
         with:
           distribution: temurin # Temurin is a distribution of adoptium
-          java-version: 11
+          java-version: 21
       - uses: actions/checkout@v3
       - uses: aws-actions/configure-aws-credentials@v1.7.0
         with:
diff --git a/.github/workflows/sql-pitest.yml b/.github/workflows/sql-pitest.yml
index bc751daefa..a1281a67f3 100644
--- a/.github/workflows/sql-pitest.yml
+++ b/.github/workflows/sql-pitest.yml
@@ -21,8 +21,7 @@ jobs:
     strategy:
       matrix:
         java:
-          - 11
-          - 17
+          - 21
     runs-on: ubuntu-latest
     container:
       # using the same image which is used by opensearch-build team to build the OpenSearch Distribution
diff --git a/.github/workflows/sql-test-and-build-workflow.yml b/.github/workflows/sql-test-and-build-workflow.yml
index ded974bfcb..f08643952d 100644
--- a/.github/workflows/sql-test-and-build-workflow.yml
+++ b/.github/workflows/sql-test-and-build-workflow.yml
@@ -29,8 +29,6 @@ jobs:
       fail-fast: false
       matrix:
         java:
-          - 11
-          - 17
           - 21
     runs-on: ubuntu-latest
     container:
@@ -105,8 +103,6 @@ jobs:
       fail-fast: false
       matrix:
         entry:
-          - { os: windows-latest, java: 11, os_build_args: -x doctest  -PbuildPlatform=windows }
-          - { os: windows-latest, java: 17, os_build_args: -x doctest -PbuildPlatform=windows }
           - { os: windows-latest, java: 21, os_build_args: -x doctest -PbuildPlatform=windows }
     runs-on: ${{ matrix.entry.os }}
 
diff --git a/.github/workflows/sql-test-workflow.yml b/.github/workflows/sql-test-workflow.yml
index 46c1930cc8..c447d968bd 100644
--- a/.github/workflows/sql-test-workflow.yml
+++ b/.github/workflows/sql-test-workflow.yml
@@ -21,8 +21,7 @@ jobs:
     strategy:
       matrix:
         java:
-          - 11
-          - 17
+          - 21
     runs-on: ubuntu-latest
     container:
       # using the same image which is used by opensearch-build team to build the OpenSearch Distribution
diff --git a/build.gradle b/build.gradle
index 3e180d4042..b3e09d7b50 100644
--- a/build.gradle
+++ b/build.gradle
@@ -112,7 +112,7 @@ allprojects {
     }
 
     plugins.withId('java') {
-        sourceCompatibility = targetCompatibility = "11"
+        sourceCompatibility = targetCompatibility = JavaVersion.VERSION_21
     }
     configurations.all {
         resolutionStrategy.force "org.jetbrains.kotlin:kotlin-stdlib:1.9.10"
diff --git a/integ-test/build.gradle b/integ-test/build.gradle
index a0f82b6f1b..93857c3817 100644
--- a/integ-test/build.gradle
+++ b/integ-test/build.gradle
@@ -194,6 +194,11 @@ dependencies {
     zipArchive group: 'org.opensearch.plugin', name:'opensearch-sql-plugin', version: "${bwcVersion}-SNAPSHOT"
 }
 
+java {
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
+}
+
 dependencyLicenses.enabled = false
 testingConventions.enabled = false
 forbiddenApisTest.enabled = false
diff --git a/plugin/build.gradle b/plugin/build.gradle
index ed6fe53247..710d81ed0a 100644
--- a/plugin/build.gradle
+++ b/plugin/build.gradle
@@ -172,6 +172,11 @@ ext {
     noticeFile = rootProject.file('NOTICE')
 }
 
+java {
+    sourceCompatibility = JavaVersion.VERSION_21
+    targetCompatibility = JavaVersion.VERSION_21
+}
+
 // ANTLR generated parser file is too large to be checked which caused licenseHeaders stuck.
 licenseHeaders {
     enabled = true
@@ -282,3 +287,4 @@ testClusters.integTest {
 run {
     useCluster testClusters.integTest
 }
+