diff --git a/firebase-functions/CHANGELOG.md b/firebase-functions/CHANGELOG.md
index 829bf9a431c..8084fc6c549 100644
--- a/firebase-functions/CHANGELOG.md
+++ b/firebase-functions/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Unreleased
 
+- [changed] Bumped dependency on OkHTTP to version 4.12.0 from version 3.12.13. If your app depends
+  on OkHTTP version 3.x the change is both binary- and Java source-compatible, with a few small
+  exceptions. See https://square.github.io/okhttp/changelogs/upgrading_to_okhttp_4/ for more
+  details.
+
 # 22.0.1
 
 - [changed] Bumped internal dependencies.
diff --git a/firebase-functions/gradle.properties b/firebase-functions/gradle.properties
index ad317096e94..4d98af6827e 100644
--- a/firebase-functions/gradle.properties
+++ b/firebase-functions/gradle.properties
@@ -1,3 +1,3 @@
-version=22.0.2
+version=22.1.0
 latestReleasedVersion=22.0.1
 android.enableUnitTestBinaryResources=true
diff --git a/firebase-functions/src/main/java/com/google/firebase/functions/FirebaseFunctions.kt b/firebase-functions/src/main/java/com/google/firebase/functions/FirebaseFunctions.kt
index 8839763c4a3..b747456aa75 100644
--- a/firebase-functions/src/main/java/com/google/firebase/functions/FirebaseFunctions.kt
+++ b/firebase-functions/src/main/java/com/google/firebase/functions/FirebaseFunctions.kt
@@ -38,10 +38,10 @@ import java.util.concurrent.Executor
 import javax.inject.Named
 import okhttp3.Call
 import okhttp3.Callback
-import okhttp3.MediaType
+import okhttp3.MediaType.Companion.toMediaTypeOrNull
 import okhttp3.OkHttpClient
 import okhttp3.Request
-import okhttp3.RequestBody
+import okhttp3.RequestBody.Companion.toRequestBody
 import okhttp3.Response
 import org.json.JSONException
 import org.json.JSONObject
@@ -87,7 +87,7 @@ internal constructor(
       try {
         URL(regionOrCustomDomain)
         false
-      } catch (malformedURLException: MalformedURLException) {
+      } catch (_: MalformedURLException) {
         true
       }
     if (isRegion) {
@@ -227,8 +227,8 @@ internal constructor(
     val encoded = serializer.encode(data)
     body["data"] = encoded
     val bodyJSON = JSONObject(body)
-    val contentType = MediaType.parse("application/json")
-    val requestBody = RequestBody.create(contentType, bodyJSON.toString())
+    val contentType = "application/json".toMediaTypeOrNull()
+    val requestBody = bodyJSON.toString().toRequestBody(contentType)
     var request = Request.Builder().url(url).post(requestBody)
     if (context!!.authToken != null) {
       request = request.header("Authorization", "Bearer " + context.authToken)
@@ -268,8 +268,8 @@ internal constructor(
 
         @Throws(IOException::class)
         override fun onResponse(ignored: Call, response: Response) {
-          val code = fromHttpStatus(response.code())
-          val bodyAsString = response.body()!!.string()
+          val code = fromHttpStatus(response.code)
+          val bodyAsString = response.body!!.string()
           val exception = fromResponse(code, bodyAsString, serializer)
           if (exception != null) {
             tcs.setException(exception)
diff --git a/firebase-functions/src/main/java/com/google/firebase/functions/PublisherStream.kt b/firebase-functions/src/main/java/com/google/firebase/functions/PublisherStream.kt
index d853dfbbb7b..ad5d9f84a26 100644
--- a/firebase-functions/src/main/java/com/google/firebase/functions/PublisherStream.kt
+++ b/firebase-functions/src/main/java/com/google/firebase/functions/PublisherStream.kt
@@ -28,7 +28,7 @@ import java.util.concurrent.Executor
 import java.util.concurrent.atomic.AtomicLong
 import okhttp3.Call
 import okhttp3.Callback
-import okhttp3.MediaType
+import okhttp3.MediaType.Companion.toMediaTypeOrNull
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.RequestBody
@@ -133,7 +133,7 @@ internal class PublisherStream(
       val configuredClient = options.apply(client)
       val requestBody =
         RequestBody.create(
-          MediaType.parse("application/json"),
+          "application/json".toMediaTypeOrNull(),
           JSONObject(mapOf("data" to serializer.encode(data))).toString()
         )
       val request =
@@ -167,7 +167,7 @@ internal class PublisherStream(
 
           override fun onResponse(call: Call, response: Response) {
             validateResponse(response)
-            val bodyStream = response.body()?.byteStream()
+            val bodyStream = response.body?.byteStream()
             if (bodyStream != null) {
               processSSEStream(bodyStream)
             } else {
@@ -309,21 +309,21 @@ internal class PublisherStream(
 
     val errorMessage: String
     if (
-      response.code() == 404 &&
-        MediaType.parse(response.header("Content-Type") ?: "")?.subtype() == "html"
+      response.code == 404 &&
+        (response.header("Content-Type") ?: "").toMediaTypeOrNull()?.subtype == "html"
     ) {
-      errorMessage = """URL not found. Raw response: ${response.body()?.string()}""".trimMargin()
+      errorMessage = """URL not found. Raw response: ${response.body?.string()}""".trimMargin()
       notifyError(
         FirebaseFunctionsException(
           errorMessage,
-          FirebaseFunctionsException.Code.fromHttpStatus(response.code()),
+          FirebaseFunctionsException.Code.fromHttpStatus(response.code),
           null
         )
       )
       return
     }
 
-    val text = response.body()?.string() ?: ""
+    val text = response.body?.string() ?: ""
     val error: Any?
     try {
       val json = JSONObject(text)
diff --git a/firebase-perf/CHANGELOG.md b/firebase-perf/CHANGELOG.md
index b859ec94029..71fb3dce42d 100644
--- a/firebase-perf/CHANGELOG.md
+++ b/firebase-perf/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Unreleased
 
+- [changed] Bumped dependency on OkHTTP to version 4.12.0 from version 3.12.13. If your app depends
+  on OkHTTP version 3.x the change is both binary- and Java source-compatible, with a few small
+  exceptions. See https://square.github.io/okhttp/changelogs/upgrading_to_okhttp_4/ for more
+  details.
+
 # 22.0.2
 
 - [changed] Bumped internal dependencies.
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index f4885496b15..5e1762ea048 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -166,7 +166,7 @@ maven-resolver-provider = { module = "org.apache.maven:maven-resolver-provider",
 maven-resolver-transport-file = { module = "org.apache.maven.resolver:maven-resolver-transport-file", version.ref = "mavenResolverApi" }
 maven-resolver-transport-http = { module = "org.apache.maven.resolver:maven-resolver-transport-http", version.ref = "mavenResolverApi" }
 maven-resolver-util = { module = "org.apache.maven.resolver:maven-resolver-util", version.ref = "mavenResolverApi" }
-okhttp = { module = "com.squareup.okhttp3:okhttp", version = "3.12.13" }
+okhttp = { module = "com.squareup.okhttp3:okhttp", version = "4.12.0" }
 org-json = { module = "org.json:json", version = "20240303" }
 play-services-cloud-messaging = { module = "com.google.android.gms:play-services-cloud-messaging", version.ref = "playServicesCloudMessaging" }
 play-services-stats = { module = "com.google.android.gms:play-services-stats", version.ref = "playServicesStats" }
@@ -222,13 +222,13 @@ wiremock-standalone = { module = "com.github.tomakehurst:wiremock-standalone", v
 kotest = ["kotest-runner", "kotest-assertions", "kotest-property", "kotest-property-arbs"]
 playservices = ["playservices-base", "playservices-basement", "playservices-tasks"]
 maven-resolver = [
-	"maven-resolver-api",
-	"maven-resolver-connector-basic",
-	"maven-resolver-impl",
-	"maven-resolver-provider",
-	"maven-resolver-transport-file",
-	"maven-resolver-transport-http",
-	"maven-resolver-util"
+    "maven-resolver-api",
+    "maven-resolver-connector-basic",
+    "maven-resolver-impl",
+    "maven-resolver-provider",
+    "maven-resolver-transport-file",
+    "maven-resolver-transport-http",
+    "maven-resolver-util"
 ]
 
 [plugins]