diff --git a/clang/cmake/caches/Fuchsia-stage2.cmake b/clang/cmake/caches/Fuchsia-stage2.cmake
--- a/clang/cmake/caches/Fuchsia-stage2.cmake
+++ b/clang/cmake/caches/Fuchsia-stage2.cmake
@@ -212,14 +212,26 @@
     set(RUNTIMES_${target}-unknown-fuchsia+asan+noexcept_LIBCXXABI_ENABLE_EXCEPTIONS OFF CACHE BOOL "")
     set(RUNTIMES_${target}-unknown-fuchsia+asan+noexcept_LIBCXX_ENABLE_EXCEPTIONS OFF CACHE BOOL "")
 
+    set(RUNTIMES_${target}-unknown-fuchsia+relative-vtables_LLVM_BUILD_COMPILER_RT OFF CACHE BOOL "")
+    set(RUNTIMES_${target}-unknown-fuchsia+relative-vtables_LIBCXXABI_RELATIVE_VTABLES_ABI_ENABLED ON CACHE BOOL "")
+    set(RUNTIMES_${target}-unknown-fuchsia+relative-vtables_CMAKE_CXX_FLAGS "${RUNTIMES_${target}-unknown-fuchsia+relative-vtables_CMAKE_CXX_FLAGS} -Xclang -fexperimental-relative-c++-abi-vtables" CACHE STRING "")
+
+    set(RUNTIMES_${target}-unknown-fuchsia+relative-vtables+noexcept_LLVM_BUILD_COMPILER_RT OFF CACHE BOOL "")
+    set(RUNTIMES_${target}-unknown-fuchsia+relative-vtables+noexcept_LIBCXXABI_RELATIVE_VTABLES_ABI_ENABLED ON CACHE BOOL "")
+    set(RUNTIMES_${target}-unknown-fuchsia+relative-vtables+noexcept_CMAKE_CXX_FLAGS "${RUNTIMES_${target}-unknown-fuchsia+relative-vtables_CMAKE_CXX_FLAGS} -Xclang -fexperimental-relative-c++-abi-vtables" CACHE STRING "")
+    set(RUNTIMES_${target}-unknown-fuchsia+relative-vtables+noexcept_LIBCXXABI_ENABLE_EXCEPTIONS OFF CACHE BOOL "")
+    set(RUNTIMES_${target}-unknown-fuchsia+relative-vtables+noexcept_LIBCXX_ENABLE_EXCEPTIONS OFF CACHE BOOL "")
+
     # Use .build-id link.
     list(APPEND RUNTIME_BUILD_ID_LINK "${target}-unknown-fuchsia")
   endforeach()
 
-  set(LLVM_RUNTIME_MULTILIBS "asan;noexcept;asan+noexcept" CACHE STRING "")
+  set(LLVM_RUNTIME_MULTILIBS "asan;noexcept;asan+noexcept;relative-vtables;relative-vtables+noexcept" CACHE STRING "")
   set(LLVM_RUNTIME_MULTILIB_asan_TARGETS "x86_64-unknown-fuchsia;aarch64-unknown-fuchsia" CACHE STRING "")
   set(LLVM_RUNTIME_MULTILIB_noexcept_TARGETS "x86_64-unknown-fuchsia;aarch64-unknown-fuchsia" CACHE STRING "")
   set(LLVM_RUNTIME_MULTILIB_asan+noexcept_TARGETS "x86_64-unknown-fuchsia;aarch64-unknown-fuchsia" CACHE STRING "")
+  set(LLVM_RUNTIME_MULTILIB_relative-vtables_TARGETS "x86_64-unknown-fuchsia;aarch64-unknown-fuchsia" CACHE STRING "")
+  set(LLVM_RUNTIME_MULTILIB_relative-vtables+noexcept_TARGETS "x86_64-unknown-fuchsia;aarch64-unknown-fuchsia" CACHE STRING "")
 endif()
 
 set(LLVM_BUILTIN_TARGETS "${BUILTIN_TARGETS}" CACHE STRING "")
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
@@ -164,6 +164,12 @@
       CmdArgs.push_back("-lc");
   }
 
+  if (Args.hasFlag(options::OPT_fexperimental_relative_cxx_abi_vtables,
+                   options::OPT_fno_experimental_relative_cxx_abi_vtables,
+                   /*default=*/false)) {
+    CmdArgs.push_back("-fexperimental-relative-c++-abi-vtables");
+  }
+
   C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
                                          Exec, CmdArgs, Inputs));
 }
@@ -208,6 +214,13 @@
                           .flag("+fsanitize=address")
                           .flag("-fexceptions")
                           .flag("+fno-exceptions"));
+  // Use the relative vtables ABI.
+  Multilibs.push_back(Multilib("relative-vtables", {}, {}, 4)
+                          .flag("+fexperimental-relative-c++-abi-vtables"));
+  Multilibs.push_back(Multilib("relative-vtables+noexcept", {}, {}, 5)
+                          .flag("+fexperimental-relative-c++-abi-vtables")
+                          .flag("-fexceptions")
+                          .flag("+fno-exceptions"));
   Multilibs.FilterOut([&](const Multilib &M) {
     std::vector<std::string> RD = FilePaths(M);
     return std::all_of(RD.begin(), RD.end(), [&](std::string P) {
@@ -220,6 +233,25 @@
       Args.hasFlag(options::OPT_fexceptions, options::OPT_fno_exceptions, true),
       "fexceptions", Flags);
   addMultilibFlag(getSanitizerArgs().needsAsanRt(), "fsanitize=address", Flags);
+
+  bool UsingRelativeVtables =
+      Args.hasFlag(options::OPT_fexperimental_relative_cxx_abi_vtables,
+                   options::OPT_fno_experimental_relative_cxx_abi_vtables,
+                   /*default=*/false);
+
+  // At this point in the pipeline, -Xclang flags haven't been parsed yet, so
+  // -fexperimental-relative-c++-abi-vtables will not be parsed into an option.
+  // Instead we can just check if -Xclang was used with this as a value.
+  for (const std::string &Flag : Args.getAllArgValues(options::OPT_Xclang)) {
+    if (Flag == "-fexperimental-relative-c++-abi-vtables") {
+      UsingRelativeVtables = true;
+      break;
+    }
+  }
+
+  addMultilibFlag(UsingRelativeVtables,
+                  "fexperimental-relative-c++-abi-vtables", Flags);
+
   Multilibs.setFilePathsCallback(FilePaths);
 
   if (Multilibs.select(Flags, SelectedMultilib))
diff --git a/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/aarch64-fuchsia/c++/relative-vtables+noexcept/libc++.so b/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/aarch64-fuchsia/c++/relative-vtables+noexcept/libc++.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/aarch64-fuchsia/c++/relative-vtables/libc++.so b/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/aarch64-fuchsia/c++/relative-vtables/libc++.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/x86_64-fuchsia/c++/relative-vtables+noexcept/libc++.so b/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/x86_64-fuchsia/c++/relative-vtables+noexcept/libc++.so
new file mode 100644
diff --git a/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/x86_64-fuchsia/c++/relative-vtables/libc++.so b/clang/test/Driver/Inputs/basic_fuchsia_tree/lib/x86_64-fuchsia/c++/relative-vtables/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
@@ -86,8 +86,20 @@
 // 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-ASAN-NOEXCEPT-X86
+// RUN: %clangxx %s -### --target=x86_64-fuchsia -fexperimental-relative-c++-abi-vtables \
+// 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-RELATIVE-VTABLES-X86
+// RUN: %clangxx %s -### --target=x86_64-fuchsia -fexperimental-relative-c++-abi-vtables -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-RELATIVE-VTABLES-NOEXCEPT-X86
 // CHECK-MULTILIB-X86: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
 // CHECK-MULTILIB-ASAN-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-fuchsia{{/|\\\\}}c++{{/|\\\\}}asan"
 // CHECK-MULTILIB-NOEXCEPT-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-fuchsia{{/|\\\\}}c++{{/|\\\\}}noexcept"
 // CHECK-MULTILIB-ASAN-NOEXCEPT-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-fuchsia{{/|\\\\}}c++{{/|\\\\}}asan+noexcept"
+// CHECK-MULTILIB-RELATIVE-VTABLES-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-fuchsia{{/|\\\\}}c++{{/|\\\\}}relative-vtables"
+// CHECK-MULTILIB-RELATIVE-VTABLES-NOEXCEPT-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-fuchsia{{/|\\\\}}c++{{/|\\\\}}relative-vtables+noexcept"
 // CHECK-MULTILIB-X86: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}lib{{/|\\\\}}x86_64-fuchsia{{/|\\\\}}c++"