diff --git a/clang/lib/Driver/ToolChains/Fuchsia.cpp b/clang/lib/Driver/ToolChains/Fuchsia.cpp
--- a/clang/lib/Driver/ToolChains/Fuchsia.cpp
+++ b/clang/lib/Driver/ToolChains/Fuchsia.cpp
@@ -242,6 +242,12 @@
                           .flag("+fsanitize=hwaddress")
                           .flag("-fexceptions")
                           .flag("+fno-exceptions"));
+  // Use the default Itanium C++ ABI.
+  Multilibs.push_back(Multilib("compat", {}, {}, 12).flag("+fc++-abi=itanium"));
+  Multilibs.push_back(Multilib("compat+noexcept", {}, {}, 13)
+                          .flag("+fc++-abi=itanium")
+                          .flag("-fexceptions")
+                          .flag("+fno-exceptions"));
 
   Multilibs.FilterOut([&](const Multilib &M) {
     std::vector<std::string> RD = FilePaths(M);
@@ -263,6 +269,8 @@
                    options::OPT_fno_experimental_relative_cxx_abi_vtables,
                    /*default=*/false),
       "fexperimental-relative-c++-abi-vtables", Flags);
+  addMultilibFlag(Args.getLastArgValue(options::OPT_fcxx_abi_EQ) == "itanium",
+                  "fc++-abi=itanium", Flags);
 
   Multilibs.setFilePathsCallback(FilePaths);
 
diff --git a/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/x86_64-unknown-fuchsia/compat+noexcept/libc++.so b/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/x86_64-unknown-fuchsia/compat+noexcept/libc++.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/x86_64-unknown-fuchsia/compat/libc++.so b/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/x86_64-unknown-fuchsia/compat/libc++.so
new file mode 100644
diff --git a/clang/test/Driver/fuchsia.cpp b/clang/test/Driver/fuchsia.cpp
--- a/clang/test/Driver/fuchsia.cpp
+++ b/clang/test/Driver/fuchsia.cpp
@@ -144,6 +144,28 @@
 // RUN:     -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
 // RUN:     -fuse-ld=lld 2>&1\
 // RUN:     | FileCheck %s -check-prefixes=CHECK-MULTILIB-X86,CHECK-MULTILIB-RELATIVE-VTABLES-HWASAN-NOEXCEPT-X86
+
+// Test compat multilibs.
+// RUN: %clangxx %s -### --target=x86_64-unknown-fuchsia -fc++-abi=itanium -fno-exceptions \
+// RUN:     -ccc-install-dir %S/Inputs/basic_fuchsia_tree/bin \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
+// RUN:     -fuse-ld=lld 2>&1\
+// RUN:     | FileCheck %s -check-prefixes=CHECK-MULTILIB-X86,CHECK-MULTILIB-COMPAT-NOEXCEPT-X86
+// RUN: %clangxx %s -### --target=x86_64-unknown-fuchsia -fc++-abi=itanium \
+// RUN:     -ccc-install-dir %S/Inputs/basic_fuchsia_tree/bin \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
+// RUN:     -fuse-ld=lld 2>&1\
+// RUN:     | FileCheck %s -check-prefixes=CHECK-MULTILIB-X86,CHECK-MULTILIB-COMPAT-X86
+// RUN: %clangxx %s -### --target=x86_64-unknown-fuchsia -fc++-abi=itanium -fc++-abi=fuchsia \
+// RUN:     -ccc-install-dir %S/Inputs/basic_fuchsia_tree/bin \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
+// RUN:     -fuse-ld=lld 2>&1\
+// RUN:     | FileCheck %s -check-prefixes=CHECK-MULTILIB-X86
+// RUN: %clangxx %s -### --target=x86_64-unknown-fuchsia -fc++-abi=fuchsia -fc++-abi=itanium \
+// RUN:     -ccc-install-dir %S/Inputs/basic_fuchsia_tree/bin \
+// RUN:     -resource-dir=%S/Inputs/resource_dir_with_per_target_subdir \
+// RUN:     -fuse-ld=lld 2>&1\
+// RUN:     | FileCheck %s -check-prefixes=CHECK-MULTILIB-X86,CHECK-MULTILIB-COMPAT-X86
 // CHECK-MULTILIB-X86: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
 // CHECK-MULTILIB-ASAN-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-unknown-fuchsia{{/|\\\\}}asan"
 // CHECK-MULTILIB-NOEXCEPT-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-unknown-fuchsia{{/|\\\\}}noexcept"
@@ -156,4 +178,6 @@
 // CHECK-MULTILIB-HWASAN-NOEXCEPT-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-unknown-fuchsia{{/|\\\\}}hwasan+noexcept"
 // CHECK-MULTILIB-RELATIVE-VTABLES-HWASAN-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-unknown-fuchsia{{/|\\\\}}relative-vtables+hwasan"
 // CHECK-MULTILIB-RELATIVE-VTABLES-HWASAN-NOEXCEPT-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-unknown-fuchsia{{/|\\\\}}relative-vtables+hwasan+noexcept"
+// CHECK-MULTILIB-COMPAT-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-unknown-fuchsia{{/|\\\\}}compat"
+// CHECK-MULTILIB-COMPAT-NOEXCEPT-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-unknown-fuchsia{{/|\\\\}}compat+noexcept"
 // CHECK-MULTILIB-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-unknown-fuchsia"