diff --git a/DEPS b/DEPS
index 54c8a9c04aa..9d600dcc2ca 100644
--- a/DEPS
+++ b/DEPS
@@ -104,8 +104,9 @@ vars = {
   "devtools_rev": "f10e8df8c517fb0412b9a66c626581867c9c267d",
   "icu_rev": "43953f57b037778a1b8005564afabe214834f7bd",
   "jinja2_rev": "2222b31554f03e62600cd7e383376a7c187967a1",
-  "libcxx_rev": "44079a4cc04cdeffb9cfe8067bfb3c276fb2bab0",
-  "libcxxabi_rev": "2ce528fb5e0f92e57c97ec3ff53b75359d33af12",
+  "libcxx_rev": "bd557f6f764d1e40b62528a13b124ce740624f8f",
+  "libcxxabi_rev": "a4dda1589d37a7e4b4f7a81ebad01b1083f2e726",
+  "libc_rev": "5af39a19a1ad51ce93972cdab206dcd3ff9b6afa",
   "libprotobuf_rev": "24487dd1045c7f3d64a21f38a3f0c06cc4cf2edb",
   "markupsafe_rev": "8f45f5cfa0009d2a70589bcda0349b8cb2b72783",
   "perfetto_rev": "13ce0c9e13b0940d2476cd0cff2301708a9a2e2b",
@@ -273,6 +274,9 @@ deps = {
   Var("dart_root") + "/third_party/libcxxabi":
       Var("llvm_git") + "/llvm-project/libcxxabi" + "@" + Var("libcxxabi_rev"),
 
+  Var("dart_root") + "/third_party/libc":
+      Var("llvm_git") + "/llvm-project/libc" + "@" + Var("libc_rev"),
+
   Var("dart_root") + "/third_party/boringssl/src":
       "https://boringssl.googlesource.com/boringssl.git" +
       "@" + Var("boringssl_rev"),
diff --git a/build/secondary/third_party/libc/BUILD.gn b/build/secondary/third_party/libc/BUILD.gn
new file mode 100644
index 00000000000..3592f50b353
--- /dev/null
+++ b/build/secondary/third_party/libc/BUILD.gn
@@ -0,0 +1,16 @@
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+config("config") {
+  visibility = [ ":*" ]
+  include_dirs = [ "." ]
+  defines = [ "LIBC_NAMESPACE=__llvm_libc_dart" ]
+}
+
+group("libc") {
+  # libc is only used as a dependency of libcxx.
+  visibility = [ "//third_party/libcxx" ]
+
+  public_configs = [ ":config" ]
+}
diff --git a/build/secondary/third_party/libcxx/BUILD.gn b/build/secondary/third_party/libcxx/BUILD.gn
index c01d111df99..0fbb38a2a63 100644
--- a/build/secondary/third_party/libcxx/BUILD.gn
+++ b/build/secondary/third_party/libcxx/BUILD.gn
@@ -15,17 +15,24 @@ source_set("libcxx") {
   sources = [
     "src/algorithm.cpp",
     "src/any.cpp",
+    "src/atomic.cpp",
+    "src/barrier.cpp",
     "src/bind.cpp",
+    "src/call_once.cpp",
     "src/charconv.cpp",
     "src/chrono.cpp",
     "src/condition_variable.cpp",
     "src/condition_variable_destructor.cpp",
-    "src/debug.cpp",
+    "src/error_category.cpp",
     "src/exception.cpp",
+    "src/filesystem/directory_entry.cpp",
     "src/filesystem/directory_iterator.cpp",
-    "src/filesystem/filesystem_common.h",
+    "src/filesystem/filesystem_clock.cpp",
+    "src/filesystem/filesystem_error.cpp",
     "src/filesystem/int128_builtins.cpp",
     "src/filesystem/operations.cpp",
+    "src/filesystem/path.cpp",
+    "src/fstream.cpp",
     "src/functional.cpp",
     "src/future.cpp",
     "src/hash.cpp",
@@ -34,11 +41,17 @@ source_set("libcxx") {
     "src/iostream.cpp",
     "src/locale.cpp",
     "src/memory.cpp",
+    "src/memory_resource.cpp",
     "src/mutex.cpp",
     "src/mutex_destructor.cpp",
     "src/new.cpp",
+    "src/new_handler.cpp",
+    "src/new_helpers.cpp",
     "src/optional.cpp",
+    "src/ostream.cpp",
+    "src/print.cpp",
     "src/random.cpp",
+    "src/random_shuffle.cpp",
     "src/regex.cpp",
     "src/ryu/d2fixed.cpp",
     "src/ryu/d2s.cpp",
@@ -50,13 +63,16 @@ source_set("libcxx") {
     "src/system_error.cpp",
     "src/thread.cpp",
     "src/typeinfo.cpp",
-    "src/utility.cpp",
     "src/valarray.cpp",
     "src/variant.cpp",
     "src/vector.cpp",
+    "src/verbose_abort.cpp",
   ]
 
-  deps = [ "//third_party/libcxxabi" ]
+  deps = [
+    "//third_party/libc",
+    "//third_party/libcxxabi",
+  ]
 
   # TODO(goderbauer): remove when all sources build with LTO for android_arm64 and android_x64.
   if (is_android && (current_cpu == "arm64" || current_cpu == "x64")) {
diff --git a/build/secondary/third_party/libcxx/config/__assertion_handler b/build/secondary/third_party/libcxx/config/__assertion_handler
new file mode 100644
index 00000000000..0e9da2b7529
--- /dev/null
+++ b/build/secondary/third_party/libcxx/config/__assertion_handler
@@ -0,0 +1,8 @@
+#ifndef DART_LIBCXX_ASSERTION_HANDLER
+#define DART_LIBCXX_ASSERTION_HANDLER
+
+#include <__verbose_abort>
+
+#define _LIBCPP_ASSERTION_HANDLER(message) _LIBCPP_VERBOSE_ABORT("%s", message)
+
+#endif  // DART_LIBCXX_ASSERTION_HANDLER
diff --git a/build/secondary/third_party/libcxx/config/__config_site b/build/secondary/third_party/libcxx/config/__config_site
index 106c24fc361..607c187415d 100644
--- a/build/secondary/third_party/libcxx/config/__config_site
+++ b/build/secondary/third_party/libcxx/config/__config_site
@@ -1,31 +1,7 @@
 #ifndef _LIBCPP_CONFIG_SITE
 #define _LIBCPP_CONFIG_SITE
-
-/* #undef _LIBCPP_ABI_VERSION */
-/* #undef _LIBCPP_ABI_UNSTABLE */
-/* #undef _LIBCPP_ABI_FORCE_ITANIUM */
-/* #undef _LIBCPP_ABI_FORCE_MICROSOFT */
-/* #undef _LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT */
-/* #undef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE */
-/* #undef _LIBCPP_HAS_NO_STDIN */
-/* #undef _LIBCPP_HAS_NO_STDOUT */
-/* #undef _LIBCPP_HAS_NO_THREADS */
-/* #undef _LIBCPP_HAS_NO_MONOTONIC_CLOCK */
-/* #undef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS */
-/* #undef _LIBCPP_HAS_MUSL_LIBC */
-/* #undef _LIBCPP_HAS_THREAD_API_PTHREAD */
-/* #undef _LIBCPP_HAS_THREAD_API_EXTERNAL */
-/* #undef _LIBCPP_HAS_THREAD_API_WIN32 */
-/* #undef _LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL */
-/* #undef _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS */
-#define _LIBCPP_HAS_NO_VENDOR_AVAILABILITY_ANNOTATIONS
-/* #undef _LIBCPP_NO_VCRUNTIME */
-/* #undef _LIBCPP_TYPEINFO_COMPARISON_IMPLEMENTATION */
-/* #undef _LIBCPP_ABI_NAMESPACE */
-/* #undef _LIBCPP_HAS_NO_FILESYSTEM_LIBRARY */
-/* #undef _LIBCPP_HAS_PARALLEL_ALGORITHMS */
-/* #undef _LIBCPP_HAS_NO_RANDOM_DEVICE */
-/* #undef _LIBCPP_HAS_NO_LOCALIZATION */
+#define _LIBCPP_ABI_VERSION 1
+#define _LIBCPP_ABI_NAMESPACE _d
 
 #define _LIBCPP_REMOVE_TRANSITIVE_INCLUDES
 
@@ -36,4 +12,31 @@
 #define _LIBCPP_COMPILER_CLANG_BASED
 #endif
 
+#if defined(__APPLE__)
+#define _LIBCPP_PSTL_BACKEND_LIBDISPATCH 1
+#else
+#define _LIBCPP_PSTL_BACKEND_STD_THREAD 1
+#endif
+
+#define _LIBCPP_HARDENING_MODE_DEFAULT _LIBCPP_HARDENING_MODE_NONE
+
+#define _LIBCPP_HAS_FILESYSTEM 1
+#define _LIBCPP_HAS_LOCALIZATION 1
+#define _LIBCPP_HAS_MONOTONIC_CLOCK 1
+#define _LIBCPP_HAS_RANDOM_DEVICE 1
+#define _LIBCPP_HAS_THREADS 1
+#define _LIBCPP_HAS_VENDOR_AVAILABILITY_ANNOTATIONS 0
+#define _LIBCPP_HAS_UNICODE 1
+#define _LIBCPP_HAS_WIDE_CHARACTERS 1
+
+#ifdef _WIN32
+#define _LIBCPP_HAS_THREAD_API_PTHREAD 0
+#define _LIBCPP_HAS_THREAD_API_EXTERNAL 0
+#define _LIBCPP_HAS_THREAD_API_WIN32 1
+#else
+#define _LIBCPP_HAS_THREAD_API_PTHREAD 1
+#define _LIBCPP_HAS_THREAD_API_EXTERNAL 0
+#define _LIBCPP_HAS_THREAD_API_WIN32 0
+#endif
+
 #endif // _LIBCPP_CONFIG_SITE