diff --git a/clang-tools-extra/clangd/CMakeLists.txt b/clang-tools-extra/clangd/CMakeLists.txt
--- a/clang-tools-extra/clangd/CMakeLists.txt
+++ b/clang-tools-extra/clangd/CMakeLists.txt
@@ -29,6 +29,7 @@
   CLANGD_MALLOC_TRIM
   CLANGD_TIDY_CHECKS
   LLVM_ENABLE_ZLIB
+  LLVM_ENABLE_ZSTD
 )
 
 configure_file(
diff --git a/clang-tools-extra/clangd/test/lit.cfg.py b/clang-tools-extra/clangd/test/lit.cfg.py
--- a/clang-tools-extra/clangd/test/lit.cfg.py
+++ b/clang-tools-extra/clangd/test/lit.cfg.py
@@ -36,3 +36,6 @@
 
 if config.have_zlib:
   config.available_features.add('zlib')
+
+if config.have_zstd:
+  config.available_features.add('zstd')
diff --git a/clang-tools-extra/clangd/test/lit.site.cfg.py.in b/clang-tools-extra/clangd/test/lit.site.cfg.py.in
--- a/clang-tools-extra/clangd/test/lit.site.cfg.py.in
+++ b/clang-tools-extra/clangd/test/lit.site.cfg.py.in
@@ -17,6 +17,7 @@
 config.clangd_enable_remote = @CLANGD_ENABLE_REMOTE@
 config.clangd_tidy_checks = @CLANGD_TIDY_CHECKS@
 config.have_zlib = @LLVM_ENABLE_ZLIB@
+config.have_zstd = @LLVM_ENABLE_ZSTD@
 
 # Delegate logic to lit.cfg.py.
 lit_config.load_config(config, "@CMAKE_CURRENT_SOURCE_DIR@/lit.cfg.py")
diff --git a/clang/test/CMakeLists.txt b/clang/test/CMakeLists.txt
--- a/clang/test/CMakeLists.txt
+++ b/clang/test/CMakeLists.txt
@@ -11,6 +11,7 @@
   CLANG_SPAWN_CC1
   ENABLE_BACKTRACES
   LLVM_ENABLE_ZLIB
+  LLVM_ENABLE_ZSTD
   LLVM_ENABLE_PER_TARGET_RUNTIME_DIR
   LLVM_ENABLE_THREADS
   LLVM_WITH_Z3
diff --git a/clang/test/lit.site.cfg.py.in b/clang/test/lit.site.cfg.py.in
--- a/clang/test/lit.site.cfg.py.in
+++ b/clang/test/lit.site.cfg.py.in
@@ -21,6 +21,7 @@
 config.host_cxx = "@CMAKE_CXX_COMPILER@"
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"
 config.have_zlib = @LLVM_ENABLE_ZLIB@
+config.have_zstd = @LLVM_ENABLE_ZSTD@
 config.clang_arcmt = @CLANG_ENABLE_ARCMT@
 config.clang_default_pie_on_linux = @CLANG_DEFAULT_PIE_ON_LINUX@
 config.clang_enable_opaque_pointers = @CLANG_ENABLE_OPAQUE_POINTERS_INTERNAL@
diff --git a/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh b/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh
--- a/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh
+++ b/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh
@@ -140,6 +140,7 @@
     -DLLVM_TABLEGEN=$TBLGEN \
     -DLLVM_DEFAULT_TARGET_TRIPLE="${TARGET_TRIPLE}" \
     -DLLVM_ENABLE_ZLIB=ON \
+    -DLLVM_ENABLE_ZSTD=ON \
     -DLLVM_ENABLE_TERMINFO=OFF \
     -DLLVM_ENABLE_THREADS=OFF \
   $LLVM_SRC
diff --git a/compiler-rt/test/lit.common.cfg.py b/compiler-rt/test/lit.common.cfg.py
--- a/compiler-rt/test/lit.common.cfg.py
+++ b/compiler-rt/test/lit.common.cfg.py
@@ -218,6 +218,9 @@
 if config.have_zlib == "1":
   config.available_features.add("zlib")
 
+if config.have_zstd == "1":
+  config.available_features.add("zstd")
+
 # Use ugly construction to explicitly prohibit "clang", "clang++" etc.
 # in RUN lines.
 config.substitutions.append(
diff --git a/compiler-rt/test/lit.common.configured.in b/compiler-rt/test/lit.common.configured.in
--- a/compiler-rt/test/lit.common.configured.in
+++ b/compiler-rt/test/lit.common.configured.in
@@ -65,6 +65,7 @@
   set_default("target_suffix", "-%s" % config.target_arch)
 
 set_default("have_zlib", "@LLVM_ENABLE_ZLIB@")
+set_default("have_zstd", "@LLVM_ENABLE_ZSTD@")
 set_default("libcxx_used", "@LLVM_LIBCXX_USED@")
 
 # LLVM tools dir can be passed in lit parameters, so try to
diff --git a/flang/CMakeLists.txt b/flang/CMakeLists.txt
--- a/flang/CMakeLists.txt
+++ b/flang/CMakeLists.txt
@@ -70,6 +70,12 @@
   if(LLVM_ENABLE_ZLIB)
     find_package(ZLIB REQUIRED)
   endif()
+  
+  # If LLVM links to zstd we need the imported targets so we can too.
+  if(LLVM_ENABLE_ZSTD)
+    find_package(ZSTD REQUIRED)
+  endif()
+
   option(LLVM_ENABLE_PEDANTIC "Compile with pedantic enabled." ON)
   if(CMAKE_COMPILER_IS_GNUCXX)
     set(USE_NO_MAYBE_UNINITIALIZED 1)
diff --git a/lld/ELF/CMakeLists.txt b/lld/ELF/CMakeLists.txt
--- a/lld/ELF/CMakeLists.txt
+++ b/lld/ELF/CMakeLists.txt
@@ -6,6 +6,10 @@
   set(imported_libs ZLIB::ZLIB)
 endif()
 
+if(LLVM_ENABLE_ZSTD)
+  list(APPEND imported_libs zstd)
+endif()
+
 add_lld_library(lldELF
   AArch64ErrataFix.cpp
   Arch/AArch64.cpp
diff --git a/lld/test/lit.site.cfg.py.in b/lld/test/lit.site.cfg.py.in
--- a/lld/test/lit.site.cfg.py.in
+++ b/lld/test/lit.site.cfg.py.in
@@ -18,6 +18,7 @@
 config.target_triple = "@LLVM_TARGET_TRIPLE@"
 config.python_executable = "@Python3_EXECUTABLE@"
 config.have_zlib = @LLVM_ENABLE_ZLIB@
+config.have_zstd = @LLVM_ENABLE_ZSTD@
 config.have_libxar = @LLVM_HAVE_LIBXAR@
 config.have_libxml2 = @LLVM_ENABLE_LIBXML2@
 config.sizeof_void_p = @CMAKE_SIZEOF_VOID_P@
diff --git a/lldb/source/Plugins/Process/gdb-remote/CMakeLists.txt b/lldb/source/Plugins/Process/gdb-remote/CMakeLists.txt
--- a/lldb/source/Plugins/Process/gdb-remote/CMakeLists.txt
+++ b/lldb/source/Plugins/Process/gdb-remote/CMakeLists.txt
@@ -18,6 +18,10 @@
   list(APPEND LLDB_SYSTEM_LIBS ZLIB::ZLIB)
 endif()
 
+if(LLVM_ENABLE_ZSTD)
+  list(APPEND LLDB_SYSTEM_LIBS zstd)
+endif()
+
 add_lldb_library(lldbPluginProcessGDBRemote PLUGIN
   GDBRemoteClientBase.cpp
   GDBRemoteCommunication.cpp
diff --git a/lldb/test/Shell/lit.site.cfg.py.in b/lldb/test/Shell/lit.site.cfg.py.in
--- a/lldb/test/Shell/lit.site.cfg.py.in
+++ b/lldb/test/Shell/lit.site.cfg.py.in
@@ -16,6 +16,7 @@
 config.target_triple = "@LLVM_TARGET_TRIPLE@"
 config.python_executable = "@Python3_EXECUTABLE@"
 config.have_zlib = @LLVM_ENABLE_ZLIB@
+config.have_zstd = @LLVM_ENABLE_ZSTD@
 config.lldb_enable_lzma = @LLDB_ENABLE_LZMA@
 config.host_triple = "@LLVM_HOST_TRIPLE@"
 config.lldb_bitness = 64 if @LLDB_IS_64_BITS@ else 32
diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -438,6 +438,8 @@
 
 set(LLVM_ENABLE_ZLIB "ON" CACHE STRING "Use zlib for compression/decompression if available. Can be ON, OFF, or FORCE_ON")
 
+set(LLVM_ENABLE_ZSTD "ON" CACHE STRING "Use zstd for compression/decompression if available. Can be ON, OFF, or FORCE_ON")
+
 set(LLVM_ENABLE_CURL "OFF" CACHE STRING "Use libcurl for the HTTP client if available. Can be ON, OFF, or FORCE_ON")
 
 set(LLVM_ENABLE_HTTPLIB "OFF" CACHE STRING "Use cpp-httplib HTTP server library if available. Can be ON, OFF, or FORCE_ON")
diff --git a/llvm/cmake/config-ix.cmake b/llvm/cmake/config-ix.cmake
--- a/llvm/cmake/config-ix.cmake
+++ b/llvm/cmake/config-ix.cmake
@@ -136,6 +136,29 @@
   set(LLVM_ENABLE_ZLIB "${HAVE_ZLIB}")
 endif()
 
+if(LLVM_ENABLE_ZSTD)
+  if(LLVM_ENABLE_ZSTD STREQUAL FORCE_ON)
+    find_package(ZSTD REQUIRED)
+  elseif(NOT LLVM_USE_SANITIZER MATCHES "Memory.*")
+    find_package(ZSTD)
+  endif()
+  if(ZSTD_FOUND)
+    # Check if zstd we found is usable; for example, we may have found a 32-bit
+    # library on a 64-bit system which would result in a link-time failure.
+    cmake_push_check_state()
+    list(APPEND CMAKE_REQUIRED_INCLUDES ${ZSTD_INCLUDE_DIR})
+    list(APPEND CMAKE_REQUIRED_LIBRARIES ${ZSTD_LIBRARY})
+    check_symbol_exists(ZSTD_compress zstd.h HAVE_ZSTD)
+    cmake_pop_check_state()
+    if(LLVM_ENABLE_ZSTD STREQUAL FORCE_ON AND NOT HAVE_ZSTD)
+      message(FATAL_ERROR "Failed to configure zstd")
+    endif()
+  endif()
+  set(LLVM_ENABLE_ZSTD "${HAVE_ZSTD}")
+else()
+  set(LLVM_ENABLE_ZSTD 0)
+endif()
+
 if(LLVM_ENABLE_LIBXML2)
   if(LLVM_ENABLE_LIBXML2 STREQUAL FORCE_ON)
     find_package(LibXml2 REQUIRED)
diff --git a/llvm/cmake/modules/FindZSTD.cmake b/llvm/cmake/modules/FindZSTD.cmake
new file mode 100644
--- /dev/null
+++ b/llvm/cmake/modules/FindZSTD.cmake
@@ -0,0 +1,21 @@
+find_path(ZSTD_INCLUDE_DIR
+  NAMES zstd.h
+  HINTS ${ZSTD_ROOT_DIR}/include)
+
+find_library(ZSTD_LIBRARY
+  NAMES zstd
+  HINTS ${ZSTD_ROOT_DIR}/lib)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(
+    ZSTD DEFAULT_MSG
+    ZSTD_LIBRARY ZSTD_INCLUDE_DIR)
+
+if(ZSTD_FOUND)
+    set(ZSTD_LIBRARIES ${ZSTD_LIBRARY})
+    set(ZSTD_INCLUDE_DIRS ${ZSTD_INCLUDE_DIR})
+endif()
+
+mark_as_advanced(
+  ZSTD_INCLUDE_DIR
+  ZSTD_LIBRARY)
diff --git a/llvm/cmake/modules/LLVMConfig.cmake.in b/llvm/cmake/modules/LLVMConfig.cmake.in
--- a/llvm/cmake/modules/LLVMConfig.cmake.in
+++ b/llvm/cmake/modules/LLVMConfig.cmake.in
@@ -73,6 +73,12 @@
   find_package(ZLIB)
 endif()
 
+set(LLVM_ENABLE_ZSTD @LLVM_ENABLE_ZSTD@)
+if(LLVM_ENABLE_ZSTD)
+  set(ZSTD_ROOT @ZSTD_ROOT@)
+  find_package(ZSTD)
+endif()
+
 set(LLVM_ENABLE_LIBXML2 @LLVM_ENABLE_LIBXML2@)
 if(LLVM_ENABLE_LIBXML2)
   find_package(LibXml2)
diff --git a/llvm/include/llvm/Config/llvm-config.h.cmake b/llvm/include/llvm/Config/llvm-config.h.cmake
--- a/llvm/include/llvm/Config/llvm-config.h.cmake
+++ b/llvm/include/llvm/Config/llvm-config.h.cmake
@@ -95,6 +95,9 @@
 /* Define if zlib compression is available */
 #cmakedefine01 LLVM_ENABLE_ZLIB
 
+/* Define if zstd compression is available */
+#cmakedefine01 LLVM_ENABLE_ZSTD
+
 /* Define if LLVM was built with a dependency to the libtensorflow dynamic library */
 #cmakedefine LLVM_HAVE_TF_API
 
diff --git a/llvm/include/llvm/Support/Compression.h b/llvm/include/llvm/Support/Compression.h
--- a/llvm/include/llvm/Support/Compression.h
+++ b/llvm/include/llvm/Support/Compression.h
@@ -42,6 +42,27 @@
 
 } // End of namespace zlib
 
+namespace zstd {
+
+constexpr int NoCompression = -5;
+constexpr int BestSpeedCompression = 1;
+constexpr int DefaultCompression = 5;
+constexpr int BestSizeCompression = 12;
+
+bool isAvailable();
+
+void compress(StringRef InputBuffer, SmallVectorImpl<char> &CompressedBuffer,
+              int Level = DefaultCompression);
+
+Error uncompress(StringRef InputBuffer, char *UncompressedBuffer,
+                 size_t &UncompressedSize);
+
+Error uncompress(StringRef InputBuffer,
+                 SmallVectorImpl<char> &UncompressedBuffer,
+                 size_t UncompressedSize);
+
+} // End of namespace zstd
+
 } // End of namespace compression
 
 } // End of namespace llvm
diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -25,6 +25,10 @@
   set(imported_libs ZLIB::ZLIB)
 endif()
 
+if(LLVM_ENABLE_ZSTD)
+  list(APPEND imported_libs zstd)
+endif()
+
 if( MSVC OR MINGW )
   # libuuid required for FOLDERID_Profile usage in lib/Support/Windows/Path.inc.
   # advapi32 required for CryptAcquireContextW in lib/Support/Windows/Path.inc.
diff --git a/llvm/lib/Support/Compression.cpp b/llvm/lib/Support/Compression.cpp
--- a/llvm/lib/Support/Compression.cpp
+++ b/llvm/lib/Support/Compression.cpp
@@ -20,6 +20,9 @@
 #if LLVM_ENABLE_ZLIB
 #include <zlib.h>
 #endif
+#if LLVM_ENABLE_ZSTD
+#include <zstd.h>
+#endif
 
 using namespace llvm;
 using namespace llvm::compression;
@@ -57,7 +60,9 @@
   // Tell MemorySanitizer that zlib output buffer is fully initialized.
   // This avoids a false report when running LLVM with uninstrumented ZLib.
   __msan_unpoison(CompressedBuffer.data(), CompressedSize);
-  CompressedBuffer.truncate(CompressedSize);
+  if (CompressedSize < CompressedBuffer.size()) {
+    CompressedBuffer.truncate(CompressedSize);
+  }
 }
 
 Error zlib::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
@@ -79,7 +84,9 @@
   UncompressedBuffer.resize_for_overwrite(UncompressedSize);
   Error E = zlib::uncompress(InputBuffer, UncompressedBuffer.data(),
                              UncompressedSize);
-  UncompressedBuffer.truncate(UncompressedSize);
+  if (UncompressedSize < UncompressedBuffer.size()) {
+    UncompressedBuffer.truncate(UncompressedSize);
+  }
   return E;
 }
 
@@ -99,3 +106,67 @@
   llvm_unreachable("zlib::uncompress is unavailable");
 }
 #endif
+
+#if LLVM_ENABLE_ZSTD
+
+bool zstd::isAvailable() { return true; }
+
+void zstd::compress(StringRef InputBuffer,
+                    SmallVectorImpl<char> &CompressedBuffer, int Level) {
+  unsigned long CompressedBufferSize = ::ZSTD_compressBound(InputBuffer.size());
+  CompressedBuffer.resize_for_overwrite(CompressedBufferSize);
+  unsigned long CompressedSize = ::ZSTD_compress(
+      (char *)CompressedBuffer.data(), CompressedBufferSize,
+      (const char *)InputBuffer.data(), InputBuffer.size(), Level);
+  if (ZSTD_isError(CompressedSize))
+    report_bad_alloc_error("Allocation failed");
+  // Tell MemorySanitizer that zstd output buffer is fully initialized.
+  // This avoids a false report when running LLVM with uninstrumented ZLib.
+  __msan_unpoison(CompressedBuffer.data(), CompressedSize);
+  if (CompressedSize < CompressedBuffer.size()) {
+    CompressedBuffer.truncate(CompressedSize);
+  }
+}
+
+Error zstd::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
+                       size_t &UncompressedSize) {
+  size_t const Res =
+      ::ZSTD_decompress((char *)UncompressedBuffer, UncompressedSize,
+                        (const char *)InputBuffer.data(), InputBuffer.size());
+  UncompressedSize = Res;
+  // Tell MemorySanitizer that zstd output buffer is fully initialized.
+  // This avoids a false report when running LLVM with uninstrumented ZLib.
+  __msan_unpoison(UncompressedBuffer, UncompressedSize);
+  return ZSTD_isError(Res) ? make_error<StringError>(ZSTD_getErrorName(Res),
+                                                     inconvertibleErrorCode())
+                           : Error::success();
+}
+
+Error zstd::uncompress(StringRef InputBuffer,
+                       SmallVectorImpl<char> &UncompressedBuffer,
+                       size_t UncompressedSize) {
+  UncompressedBuffer.resize_for_overwrite(UncompressedSize);
+  Error E = zstd::uncompress(InputBuffer, UncompressedBuffer.data(),
+                             UncompressedSize);
+  if (UncompressedSize < UncompressedBuffer.size()) {
+    UncompressedBuffer.truncate(UncompressedSize);
+  }
+  return E;
+}
+
+#else
+bool zstd::isAvailable() { return false; }
+void zstd::compress(StringRef InputBuffer,
+                    SmallVectorImpl<char> &CompressedBuffer, int Level) {
+  llvm_unreachable("zstd::compress is unavailable");
+}
+Error zstd::uncompress(StringRef InputBuffer, char *UncompressedBuffer,
+                       size_t &UncompressedSize) {
+  llvm_unreachable("zstd::uncompress is unavailable");
+}
+Error zstd::uncompress(StringRef InputBuffer,
+                       SmallVectorImpl<char> &UncompressedBuffer,
+                       size_t UncompressedSize) {
+  llvm_unreachable("zstd::uncompress is unavailable");
+}
+#endif
diff --git a/llvm/test/lit.site.cfg.py.in b/llvm/test/lit.site.cfg.py.in
--- a/llvm/test/lit.site.cfg.py.in
+++ b/llvm/test/lit.site.cfg.py.in
@@ -37,6 +37,7 @@
 config.llvm_use_intel_jitevents = @LLVM_USE_INTEL_JITEVENTS@
 config.llvm_use_sanitizer = "@LLVM_USE_SANITIZER@"
 config.have_zlib = @LLVM_ENABLE_ZLIB@
+config.have_zstd = @LLVM_ENABLE_ZSTD@
 config.have_libxar = @LLVM_HAVE_LIBXAR@
 config.have_libxml2 = @LLVM_ENABLE_LIBXML2@
 config.have_curl = @LLVM_ENABLE_CURL@
diff --git a/llvm/unittests/Support/CompressionTest.cpp b/llvm/unittests/Support/CompressionTest.cpp
--- a/llvm/unittests/Support/CompressionTest.cpp
+++ b/llvm/unittests/Support/CompressionTest.cpp
@@ -65,4 +65,46 @@
 
 #endif
 
+#if LLVM_ENABLE_ZSTD
+
+void TestZstdCompression(StringRef Input, int Level) {
+  SmallString<32> Compressed;
+  SmallString<32> Uncompressed;
+
+  zstd::compress(Input, Compressed, Level);
+
+  // Check that uncompressed buffer is the same as original.
+  Error E = zstd::uncompress(Compressed, Uncompressed, Input.size());
+  consumeError(std::move(E));
+
+  EXPECT_EQ(Input, Uncompressed);
+  if (Input.size() > 0) {
+    // Uncompression fails if expected length is too short.
+    E = zstd::uncompress(Compressed, Uncompressed, Input.size() - 1);
+    EXPECT_EQ("Destination buffer is too small", llvm::toString(std::move(E)));
+  }
+}
+
+TEST(CompressionTest, Zstd) {
+  TestZstdCompression("", zstd::DefaultCompression);
+
+  TestZstdCompression("hello, world!", zstd::NoCompression);
+  TestZstdCompression("hello, world!", zstd::BestSizeCompression);
+  TestZstdCompression("hello, world!", zstd::BestSpeedCompression);
+  TestZstdCompression("hello, world!", zstd::DefaultCompression);
+
+  const size_t kSize = 1024;
+  char BinaryData[kSize];
+  for (size_t i = 0; i < kSize; ++i) {
+    BinaryData[i] = i & 255;
+  }
+  StringRef BinaryDataStr(BinaryData, kSize);
+
+  TestZstdCompression(BinaryDataStr, zstd::NoCompression);
+  TestZstdCompression(BinaryDataStr, zstd::BestSizeCompression);
+  TestZstdCompression(BinaryDataStr, zstd::BestSpeedCompression);
+  TestZstdCompression(BinaryDataStr, zstd::DefaultCompression);
+}
+
+#endif
 }
diff --git a/utils/bazel/llvm_configs/llvm-config.h.cmake b/utils/bazel/llvm_configs/llvm-config.h.cmake
--- a/utils/bazel/llvm_configs/llvm-config.h.cmake
+++ b/utils/bazel/llvm_configs/llvm-config.h.cmake
@@ -95,6 +95,9 @@
 /* Define if zlib compression is available */
 #cmakedefine01 LLVM_ENABLE_ZLIB
 
+/* Define if zstd compression is available */
+#cmakedefine01 LLVM_ENABLE_ZSTD
+
 /* Define if LLVM was built with a dependency to the libtensorflow dynamic library */
 #cmakedefine LLVM_HAVE_TF_API