diff --git a/src/ray/core_worker/actor_manager.cc b/src/ray/core_worker/actor_manager.cc
index 4346d1eff96d..f3d354dbc439 100644
--- a/src/ray/core_worker/actor_manager.cc
+++ b/src/ray/core_worker/actor_manager.cc
@@ -205,7 +205,19 @@ bool ActorManager::AddActorHandle(std::unique_ptr<ActorHandle> actor_handle,
 }
 
 void ActorManager::OnActorKilled(const ActorID &actor_id) {
-  MarkActorKilledOrOutOfScope(GetActorHandle(actor_id));
+  auto actor_handle = GetActorHandleIfExists(actor_id);
+  if (actor_handle == nullptr) {
+    // The actor handle may not exist if:
+    // 1. The actor was created in a previous Ray session and the user is trying
+    //    to kill it after ray.shutdown() and ray.init().
+    // 2. The actor handle was already removed for some other reason.
+    // In these cases, we simply log a warning and return instead of crashing.
+    RAY_LOG(WARNING) << "Cannot find actor handle for actor_id " << actor_id
+                     << ". The actor may have been created in a different Ray session "
+                     << "or already been cleaned up.";
+    return;
+  }
+  MarkActorKilledOrOutOfScope(actor_handle);
 }
 
 void ActorManager::WaitForActorRefDeleted(
diff --git a/src/ray/core_worker/tests/actor_manager_test.cc b/src/ray/core_worker/tests/actor_manager_test.cc
index 79e46745454b..194c29353e7f 100644
--- a/src/ray/core_worker/tests/actor_manager_test.cc
+++ b/src/ray/core_worker/tests/actor_manager_test.cc
@@ -393,6 +393,23 @@ TEST_F(ActorManagerTest, TestNamedActorIsKilledBeforeSubscribeFinished) {
   ASSERT_TRUE(actor_manager_->GetCachedNamedActorID(cached_actor_name).IsNil());
 }
 
+// Test that OnActorKilled does not crash when the actor handle does not exist.
+// This can happen when the actor was created in a previous Ray session.
+// Fixes https://github.com/ray-project/ray/issues/59340
+TEST_F(ActorManagerTest, TestOnActorKilledWithNonExistentHandle) {
+  // Create a random actor ID that does not have a registered handle.
+  ActorID non_existent_actor_id = ActorID::Of(JobID::FromInt(1), TaskID::Nil(), 1);
+
+  // Verify that the actor handle does not exist.
+  ASSERT_FALSE(actor_manager_->CheckActorHandleExists(non_existent_actor_id));
+
+  // Call OnActorKilled with a non-existent actor ID.
+  // This should NOT crash - it should log a warning and return gracefully.
+  actor_manager_->OnActorKilled(non_existent_actor_id);
+
+  // The test passes if we reach here without crashing.
+}
+
 }  // namespace core
 }  // namespace ray