diff --git a/lld/MachO/Config.h b/lld/MachO/Config.h
--- a/lld/MachO/Config.h
+++ b/lld/MachO/Config.h
@@ -151,6 +151,7 @@
   bool deadStrip = false;
   bool errorForArchMismatch = false;
   PlatformInfo platformInfo;
+  llvm::Optional<PlatformInfo> secondaryPlatformInfo;
   NamespaceKind namespaceKind = NamespaceKind::twolevel;
   UndefinedSymbolTreatment undefinedSymbolTreatment =
       UndefinedSymbolTreatment::error;
diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -642,12 +642,27 @@
     return PLATFORM_UNKNOWN;
   }
   if (platformVersions.size() == 2) {
-    // FIXME: If you implement support for this, add a diagnostic if
-    // outputType is not dylib or bundle -- linkers shouldn't be able to
-    // write zippered executables.
-    warn("writing zippered outputs not yet implemented, "
-         "ignoring all but last -platform_version flag");
+    bool isZipperedCatalyst = platformVersions.count(PLATFORM_MACOS) &&
+                              platformVersions.count(PLATFORM_MACCATALYST);
+
+    if (!isZipperedCatalyst) {
+      error("lld supports writing zippered outputs only for "
+            "macos and mac-catalyst");
+    } else if (config->outputType != MH_DYLIB &&
+               config->outputType != MH_BUNDLE) {
+      error("writing zippered outputs only valid for -dylib and -bundle");
+    } else {
+      config->platformInfo.minimum = platformVersions[PLATFORM_MACOS].minimum;
+      config->platformInfo.sdk = platformVersions[PLATFORM_MACOS].sdk;
+      config->secondaryPlatformInfo = PlatformInfo{};
+      config->secondaryPlatformInfo->minimum =
+          platformVersions[PLATFORM_MACCATALYST].minimum;
+      config->secondaryPlatformInfo->sdk =
+          platformVersions[PLATFORM_MACCATALYST].sdk;
+    }
+    return PLATFORM_MACOS;
   }
+
   config->platformInfo.minimum = lastVersionInfo->minimum;
   config->platformInfo.sdk = lastVersionInfo->sdk;
   return lastVersionInfo->platform;
@@ -664,6 +679,10 @@
   PlatformType platform = parsePlatformVersions(args);
   config->platformInfo.target =
       MachO::Target(getArchitectureFromName(archName), platform);
+  if (config->secondaryPlatformInfo) {
+    config->secondaryPlatformInfo->target =
+        MachO::Target(getArchitectureFromName(archName), PLATFORM_MACCATALYST);
+  }
 
   uint32_t cpuType;
   uint32_t cpuSubtype;
@@ -1128,6 +1147,7 @@
 
   config = std::make_unique<Configuration>();
   symtab = std::make_unique<SymbolTable>();
+  config->outputType = getOutputType(args);
   target = createTargetInfo(args);
   depTracker = std::make_unique<DependencyTracker>(
       args.getLastArgValue(OPT_dependency_info));
@@ -1234,7 +1254,6 @@
   config->printEachFile = args.hasArg(OPT_t);
   config->printWhyLoad = args.hasArg(OPT_why_load);
   config->omitDebugInfo = args.hasArg(OPT_S);
-  config->outputType = getOutputType(args);
   config->errorForArchMismatch = args.hasArg(OPT_arch_errors_fatal);
   if (const Arg *arg = args.getLastArg(OPT_bundle_loader)) {
     if (config->outputType != MH_BUNDLE)
diff --git a/lld/MachO/Writer.cpp b/lld/MachO/Writer.cpp
--- a/lld/MachO/Writer.cpp
+++ b/lld/MachO/Writer.cpp
@@ -458,9 +458,11 @@
     auto *c = reinterpret_cast<build_version_command *>(buf);
     c->cmd = LC_BUILD_VERSION;
     c->cmdsize = getSize();
+
     c->platform = static_cast<uint32_t>(platformInfo.target.Platform);
     c->minos = encodeVersion(platformInfo.minimum);
     c->sdk = encodeVersion(platformInfo.sdk);
+
     c->ntools = ntools;
     auto *t = reinterpret_cast<build_tool_version *>(&c[1]);
     t->tool = TOOL_LD;
@@ -768,6 +770,11 @@
   else
     in.header->addLoadCommand(make<LCMinVersion>(config->platformInfo));
 
+  if (config->secondaryPlatformInfo) {
+    in.header->addLoadCommand(
+        make<LCBuildVersion>(*config->secondaryPlatformInfo));
+  }
+
   // This is down here to match ld64's load command order.
   if (config->outputType == MH_EXECUTE)
     in.header->addLoadCommand(make<LCMain>());
diff --git a/lld/test/MachO/platform-version.s b/lld/test/MachO/platform-version.s
--- a/lld/test/MachO/platform-version.s
+++ b/lld/test/MachO/platform-version.s
@@ -61,10 +61,10 @@
 # FAIL-PLATFORM-NOT: malformed {{minimum|sdk}} version: {{.*}}
 
 # RUN: not %no-arg-lld -arch x86_64 -o %t %t.o -fatal_warnings 2>&1 \
-# RUN:        -platform_version 'mac catalyst' 14.0 15.0 \
+# RUN:        -platform_version iOS 14.0 15.0 \
 # RUN:        -platform_version macos 12.0 12.0 \
 # RUN:     | FileCheck --check-prefix=FAIL-TODO %s
-# FAIL-TODO: writing zippered outputs not yet implemented, ignoring all but last -platform_version flag
+# FAIL-TODO: lld supports writing zippered outputs only for macos and mac-catalyst
 
 # RUN: not %no-arg-lld -arch x86_64 -o %t %t.o 2>&1 \
 # RUN:        -platform_version bridgeOS 1 5 \
diff --git a/lld/test/MachO/zippered.yaml b/lld/test/MachO/zippered.yaml
--- a/lld/test/MachO/zippered.yaml
+++ b/lld/test/MachO/zippered.yaml
@@ -5,10 +5,10 @@
 # RUN: echo "" | llvm-mc -filetype=obj -triple=x86_64-apple-ios13.15.0-macabi -o %t/test_maccatalyst.o
 # RUN: echo "" | llvm-mc -filetype=obj -triple=x86_64-apple-ios13.15.0 -o %t/test_ios.o
 
+## Test linking against a zippered dylib.
 # RUN: %lld -lSystem -dylib %t/test.dylib %t/test_macos.o -o /dev/null
 # RUN: %no-arg-lld -syslibroot %S/Inputs/MacOSX.sdk -lSystem -dylib -arch x86_64 -platform_version mac-catalyst 13.15.0 14.0 %t/test.dylib %t/test_maccatalyst.o -o /dev/null
 
-
 # RUN: %no-arg-lld -syslibroot %S/Inputs/MacOSX.sdk -lSystem -dylib -arch x86_64 -platform_version mac-catalyst 13.15.0 14.0 %t/test_maccatalyst.o -o /dev/null -framework MacOnly-Indirect
 
 # RUN: not %no-arg-lld -syslibroot %S/Inputs/MacOSX.sdk -lSystem -dylib -arch x86_64 -platform_version mac-catalyst 13.15.0 14.0 %t/test_maccatalyst.o -o /dev/null -framework MacOnly 2>&1 | FileCheck --check-prefix=INCOMPATIBLE %s
@@ -17,6 +17,50 @@
 # RUN: not %no-arg-lld -syslibroot %S/Inputs/MacOSX.sdk -lSystem -dylib -arch x86_64 -platform_version ios 13.15.0 14.0 %t/test.dylib %t/test_ios.o -o /dev/null 2>&1 | FileCheck %s
 # CHECK: test.dylib has platform macOS/macCatalyst, which is different from target platform iOS
 
+## Test creating a zippered dylib.
+# RUN: %no-arg-lld -syslibroot %S/Inputs/MacOSX.sdk -lSystem -dylib -arch x86_64 -platform_version macos 12.0 13.0 -platform_version mac-catalyst 13.15.0 14.0 %t/test.dylib %t/test_macos.o -o %t/test_zippered.dylib
+# RUN: llvm-otool -l %t/test_zippered.dylib | FileCheck --check-prefix=ZIPPERED %s
+# ZIPPERED:           cmd LC_BUILD_VERSION
+# ZIPPERED-NEXT:  cmdsize
+# ZIPPERED-NEXT: platform 1
+# ZIPPERED-NEXT:      sdk 13.0
+# ZIPPERED-NEXT:    minos 12.0
+# ZIPPERED-NEXT:   ntools 1
+# ZIPPERED-NEXT:     tool
+# ZIPPERED-NEXT:  version
+# ZIPPERED-NEXT: Load command
+# ZIPPERED-NEXT:      cmd LC_BUILD_VERSION
+# ZIPPERED-NEXT:  cmdsize
+# ZIPPERED-NEXT: platform 6
+# ZIPPERED-NEXT:      sdk 14.0
+# ZIPPERED-NEXT:    minos 13.15
+# ZIPPERED-NEXT:   ntools 1
+# ZIPPERED-NEXT:     tool
+# ZIPPERED-NEXT:  version
+
+# RUN: %no-arg-lld -syslibroot %S/Inputs/MacOSX.sdk -lSystem -dylib -arch x86_64 -platform_version macos 10.8 13.0 -platform_version mac-catalyst 13.15.0 14.0 %t/test.dylib %t/test_macos.o -o %t/test_zippered.dylib
+# RUN: llvm-otool -l %t/test_zippered.dylib | FileCheck --check-prefix=ZIPPERED-OLD %s
+# ZIPPERED-OLD:           cmd LC_VERSION_MIN_MACOSX
+# ZIPPERED-OLD-NEXT:  cmdsize
+# ZIPPERED-OLD-NEXT:  version 10.8
+# ZIPPERED-OLD-NEXT:      sdk 13.0
+# ZIPPERED-OLD-NEXT: Load command
+# ZIPPERED-OLD-NEXT:      cmd LC_BUILD_VERSION
+# ZIPPERED-OLD-NEXT:  cmdsize
+# ZIPPERED-OLD-NEXT: platform 6
+# ZIPPERED-OLD-NEXT:      sdk 14.0
+# ZIPPERED-OLD-NEXT:    minos 13.15
+# ZIPPERED-OLD-NEXT:   ntools 1
+# ZIPPERED-OLD-NEXT:     tool
+# ZIPPERED-OLD-NEXT:  version
+
+# RUN: not %no-arg-lld -syslibroot %S/Inputs/MacOSX.sdk -lSystem -arch x86_64 -platform_version macos 10.8 13.0 -platform_version mac-catalyst 13.15.0 14.0 %t/test.dylib %t/test_macos.o -o %t/test_zippered.dylib 2>&1 | FileCheck --check-prefix=ZIPPERED-EXE %s
+# ZIPPERED-EXE: writing zippered outputs only valid for -dylib and -bundle
+
+## Reject .o files which only have the secondary platform.
+# RUN: not %no-arg-lld -syslibroot %S/Inputs/MacOSX.sdk -lSystem -dylib -arch x86_64 -platform_version macos 12.0 13.0 -platform_version mac-catalyst 13.15.0 14.0 %t/test.dylib %t/test_maccatalyst.o -o %t/test_zippered.dylib 2>&1 | FileCheck --check-prefix=CAT %s
+# CAT: test_maccatalyst.o has platform macCatalyst, which is different from target platform macOS
+
 --- !mach-o
 FileHeader:
   magic:           0xFEEDFACF