diff --git a/.github/workflows/dep_build_v2.yml b/.github/workflows/dep_build_v2.yml
index 48ef8416a..87127e4e1 100644
--- a/.github/workflows/dep_build_v2.yml
+++ b/.github/workflows/dep_build_v2.yml
@@ -16,9 +16,7 @@ jobs:
       matrix:
         java_version: ['8', '17', '21', '23']
         # Versions need to align with ones in 'main.yml' workflow
-        # kotlin-reflect 1.8.2x has a bug and some tests fail, so we are downgrading to 1.8.10.
-        # https://youtrack.jetbrains.com/issue/KT-65156
-        kotlin_version: ['1.8.10', '1.9.24', '2.0.21', '2.1.0']
+        kotlin_version: ['1.9.24', '2.0.21', '2.1.0']
     env:
       JAVA_OPTS: "-XX:+TieredCompilation -XX:TieredStopAtLevel=1"
     steps:
diff --git a/.github/workflows/dep_build_v3.yml b/.github/workflows/dep_build_v3.yml
index 2379d3230..96b000383 100644
--- a/.github/workflows/dep_build_v3.yml
+++ b/.github/workflows/dep_build_v3.yml
@@ -16,9 +16,7 @@ jobs:
       matrix:
         java_version: ['8', '17', '21', '23']
         # Versions need to align with ones in 'main.yml' workflow
-        # kotlin-reflect 1.8.2x has a bug and some tests fail, so we are downgrading to 1.8.10.
-        # https://youtrack.jetbrains.com/issue/KT-65156
-        kotlin_version: ['1.8.10', '1.9.24', '2.0.21', '2.1.0']
+        kotlin_version: ['1.9.24', '2.0.21', '2.1.0']
     env:
       JAVA_OPTS: "-XX:+TieredCompilation -XX:TieredStopAtLevel=1"
     steps:
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index d7d10f6fc..55175e67a 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -28,12 +28,10 @@ jobs:
       max-parallel: 5
       matrix:
         java_version: ['8', '11', '17', '21', '23']
-        # kotlin-reflect 1.8.2x has a bug and some tests fail, so we are downgrading to 1.8.10.
-        # https://youtrack.jetbrains.com/issue/KT-65156
-        kotlin_version: ['1.8.10', '1.9.24', '2.0.21', '2.1.0']
+        kotlin_version: ['1.9.24', '2.0.21', '2.1.0']
         include:
           - java_version: '8'
-            kotlin_version: '1.8.10'
+            kotlin_version: '1.9.24'
             release_build: 'R'
     env:
       JAVA_OPTS: "-XX:+TieredCompilation -XX:TieredStopAtLevel=1"
diff --git a/README.md b/README.md
index b0f58245d..bf9d3a1fd 100644
--- a/README.md
+++ b/README.md
@@ -111,6 +111,7 @@ println(arrayNode.toString()) // ["foo",true,1,1.0,"YmFy"]
 Different `kotlin-core` versions are supported by different Jackson Kotlin module minor versions.
 Here is an incomplete list of supported versions:
 
+* Jackson 2.19.x: Kotlin-core 1.9 - 2.1
 * Jackson 2.18.x: Kotlin-core 1.8 - 2.1
 * Jackson 2.17.x: Kotlin-core 1.7 - 2.0
 * Jackson 2.16.x: Kotlin-core 1.6 - 1.9
diff --git a/pom.xml b/pom.xml
index 4671fb048..0e954c6cc 100644
--- a/pom.xml
+++ b/pom.xml
@@ -62,9 +62,7 @@
         <javac.src.version>1.8</javac.src.version>
         <javac.target.version>1.8</javac.target.version>
 
-        <!-- kotlin-reflect 1.8.2x has a bug and some tests fail, so we are downgrading to 1.8.10. -->
-        <!-- https://youtrack.jetbrains.com/issue/KT-65156 -->
-        <version.kotlin>1.8.10</version.kotlin>
+        <version.kotlin>1.9.24</version.kotlin>
 
         <!-- Generate PackageVersion.java into this directory. -->
         <packageVersion.dir>com/fasterxml/jackson/module/kotlin</packageVersion.dir>
diff --git a/release-notes/CREDITS-2.x b/release-notes/CREDITS-2.x
index 7769c55b5..a64d02a3f 100644
--- a/release-notes/CREDITS-2.x
+++ b/release-notes/CREDITS-2.x
@@ -18,6 +18,7 @@ Contributors:
 # 2.19.0 (not yet released)
 
 WrongWrong (@k163377)
+* #861: Update Kotlin to 1.9.24
 * #858: Refactor findDefaultCreator
 * #839: Remove useKotlinPropertyNameForGetter and unify with kotlinPropertyNameAsImplicitName
 * #835: Remove old SingletonSupport class and unified with KotlinFeature.SingletonSupport
diff --git a/release-notes/VERSION-2.x b/release-notes/VERSION-2.x
index 6995f8b83..3cb0111eb 100644
--- a/release-notes/VERSION-2.x
+++ b/release-notes/VERSION-2.x
@@ -18,6 +18,7 @@ Co-maintainers:
 
 2.19.0 (not yet released)
 
+#861: Kotlin has been upgraded to 1.9.24.
 #858: Minor performance improvement of findDefaultCreator in edge cases.
 #839: Remove useKotlinPropertyNameForGetter and unify with kotlinPropertyNameAsImplicitName.
 #835: Remove old SingletonSupport class and unified with KotlinFeature.SingletonSupport.