diff --git a/llvm/include/llvm/TargetParser/Triple.h b/llvm/include/llvm/TargetParser/Triple.h
--- a/llvm/include/llvm/TargetParser/Triple.h
+++ b/llvm/include/llvm/TargetParser/Triple.h
@@ -225,7 +225,8 @@
     Emscripten,
     ShaderModel, // DirectX ShaderModel
     LiteOS,
-    LastOSType = LiteOS
+    Serenity,
+    LastOSType = Serenity
   };
   enum EnvironmentType {
     UnknownEnvironment,
@@ -677,6 +678,11 @@
     return getOS() == Triple::AIX;
   }
 
+  /// Tests whether the OS is SerenityOS
+  bool isOSSerenity() const {
+    return getOS() == Triple::Serenity;
+  }
+
   /// Tests whether the OS uses the ELF binary format.
   bool isOSBinFormatELF() const {
     return getObjectFormat() == Triple::ELF;
diff --git a/llvm/lib/TargetParser/Triple.cpp b/llvm/lib/TargetParser/Triple.cpp
--- a/llvm/lib/TargetParser/Triple.cpp
+++ b/llvm/lib/TargetParser/Triple.cpp
@@ -237,6 +237,7 @@
   case PS5: return "ps5";
   case RTEMS: return "rtems";
   case Solaris: return "solaris";
+  case Serenity: return "serenity";
   case TvOS: return "tvos";
   case UEFI: return "uefi";
   case WASI: return "wasi";
@@ -616,6 +617,7 @@
     .StartsWith("emscripten", Triple::Emscripten)
     .StartsWith("shadermodel", Triple::ShaderModel)
     .StartsWith("liteos", Triple::LiteOS)
+    .StartsWith("serenity", Triple::Serenity)
     .Default(Triple::UnknownOS);
 }