diff --git a/libcxx/include/exception b/libcxx/include/exception
--- a/libcxx/include/exception
+++ b/libcxx/include/exception
@@ -84,7 +84,9 @@
 #include <type_traits>
 #include <version>
 
-#if defined(_LIBCPP_ABI_VCRUNTIME)
+// <vcruntime_exception.h> defines its own std::exception and std::bad_exception types,
+// which we use in order to be ABI-compatible with other STLs on Windows.
+#if defined(_LIBCPP_ABI_VCRUNTIME) && _HAS_EXCEPTIONS == 1
 #include <vcruntime_exception.h>
 #endif
 
@@ -95,7 +97,63 @@
 namespace std  // purposefully not using versioning namespace
 {
 
-#if !defined(_LIBCPP_ABI_VCRUNTIME)
+   //Already included above
+#if defined(_LIBCPP_ABI_VCRUNTIME) && _HAS_EXCEPTIONS == 1
+
+// However, <vcruntime_exception.h> does not define std::exception and std::bad_exception 
+// under -fno-exceptions.
+//
+// Since libc++ still wants to provide the std::exception hierarchy under -fno-exceptions
+// (after all those are simply types like any other), we define an ABI-compatible version 
+// of the VCRuntime std::exception and std::bad_exception types in that mode.
+#elif defined(_LIBCPP_ABI_VCRUNTIME) && _HAS_EXCEPTIONS == 0
+
+    // Note: details for an ABI compatable implementation were taken from:
+    // https://github.com/microsoft/STL/blob/afe0800cd6bf0d163bf678ad4e1feb3c130d1ec5/stl/inc/exception#L80
+
+class _LIBCPP_EXCEPTION_ABI exception { // base of all library exceptions
+public:
+
+    // this constructor is necessary to compile
+    // successfully header new for _HAS_EXCEPTIONS==0 scenario
+    explicit __CLR_OR_THIS_CALL exception(const char* _Message = "unknown", int = 1) _NOEXCEPT {}
+
+    __CLR_OR_THIS_CALL exception(const exception& _Right) _NOEXCEPT {}
+
+    exception& __CLR_OR_THIS_CALL operator=(const exception& _Right) _NOEXCEPT {
+        return *this;
+    }
+
+    virtual __CLR_OR_THIS_CALL ~exception() _NOEXCEPT {}
+
+    _NODISCARD virtual const char* __CLR_OR_THIS_CALL what() const _NOEXCEPT { // return pointer to message string
+        return "unknown exception";
+    }
+
+    _LIBCPP_NORETURN void __CLR_OR_THIS_CALL _Raise() const {
+    }
+
+protected:
+    virtual void __CLR_OR_THIS_CALL _Doraise() const {}
+
+protected:
+    const char* _Ptr; 
+};
+
+class _LIBCPP_EXCEPTION_ABI bad_exception : public exception {
+public:
+    __CLR_OR_THIS_CALL bad_exception(const char* _Message = "bad exception") noexcept : exception(_Message) {}
+
+    __CLR_OR_THIS_CALL ~bad_exception() noexcept override {}
+
+protected:
+    void __CLR_OR_THIS_CALL _Doraise() const override { 
+    }
+};
+
+// On all other platforms, we define our own std::exception and std::bad_exception types
+// regardless of whether exceptions are turned on as a language feature.
+#else// !defined(_LIBCPP_ABI_VCRUNTIME)
 class _LIBCPP_EXCEPTION_ABI exception
 {
 public:
diff --git a/libcxx/test/support/test_macros.h b/libcxx/test/support/test_macros.h
--- a/libcxx/test/support/test_macros.h
+++ b/libcxx/test/support/test_macros.h
@@ -185,7 +185,8 @@
 #endif
 
 #if !TEST_HAS_FEATURE(cxx_exceptions) && !defined(__cpp_exceptions) \
-     && !defined(__EXCEPTIONS)
+     && !defined(__EXCEPTIONS) \
+     || (defined(_HAS_EXCEPTIONS) && _HAS_EXCEPTIONS == 0)
 #define TEST_HAS_NO_EXCEPTIONS
 #endif
 
diff --git a/libcxx/utils/ci/buildkite-pipeline.yml b/libcxx/utils/ci/buildkite-pipeline.yml
--- a/libcxx/utils/ci/buildkite-pipeline.yml
+++ b/libcxx/utils/ci/buildkite-pipeline.yml
@@ -565,6 +565,18 @@
             limit: 2
       timeout_in_minutes: 120
 
+    - label: "Windows (_HAS_EXCEPTIONS=0)"
+      command: "bash libcxx/utils/ci/run-buildbot clang-cl-noexceptions"
+      artifact_paths:
+        - "**/test-results.xml"
+        - "**/*.abilist"
+      agents:
+        queue: "windows"
+      retry:
+        automatic:
+          - exit_status: -1  # Agent was lost
+            limit: 2
+
     - label: "MinGW (DLL)"
       command: "bash libcxx/utils/ci/run-buildbot mingw-dll"
       artifact_paths:
diff --git a/libcxx/utils/ci/run-buildbot b/libcxx/utils/ci/run-buildbot
--- a/libcxx/utils/ci/run-buildbot
+++ b/libcxx/utils/ci/run-buildbot
@@ -592,6 +592,18 @@
     echo "+++ Running the libc++ tests"
     ${NINJA} -vC "${BUILD_DIR}" check-cxx
 ;;
+clang-cl-noexceptions)
+    clean
+    # Building libc++ in the same way as in clang-cl-dll above, but running
+    # tests with -D_HAS_EXCEPTIONS=0, which users might set in certain
+    # translation units while using libc++, even if libc++ is built with
+    # exceptions enabled.
+    generate-cmake-libcxx-win  -DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=OFF \
+                               -DLIBCXX_TEST_COMPILER_FLAGS="_HAS_EXCEPTIONS=0" \
+                               -DLIBCXX_TEST_CONFIG="llvm-libc++-shared-clangcl.cfg.in"
+    echo "+++ Running the libc++ tests"
+    ${NINJA} -vC "${BUILD_DIR}" check-cxx
+;;
 mingw-dll)
     clean
     # Explicitly specify the compiler with a triple prefix. The CI
diff --git a/libcxx/utils/libcxx/test/features.py b/libcxx/utils/libcxx/test/features.py
--- a/libcxx/utils/libcxx/test/features.py
+++ b/libcxx/utils/libcxx/test/features.py
@@ -39,6 +39,13 @@
           when=lambda cfg: hasCompileFlag(cfg, '-Wuser-defined-warnings'),
           actions=[AddCompileFlag('-Wuser-defined-warnings')]),
 
+  # Normally, the feature 'no-exceptions' is set in params.py if
+  # running tests with enable_exceptions=false, but if we didn't set
+  # that and only defined _HAS_EXCEPTIONS=0, pick up on that and set the
+  # no-exceptions feature so certain tests are omitted.
+  # It would probably be fine to just run that test configuration with
+  # enable_exceptions=false too.
+  Feature(name='no-exceptions',                 when=lambda cfg: '_HAS_EXCEPTIONS' in compilerMacros(cfg) and compilerMacros(cfg)['_HAS_EXCEPTIONS'] == '0'),
   Feature(name='has-fblocks',                   when=lambda cfg: hasCompileFlag(cfg, '-fblocks')),
   Feature(name='-fsized-deallocation',          when=lambda cfg: hasCompileFlag(cfg, '-fsized-deallocation')),
   Feature(name='-faligned-allocation',          when=lambda cfg: hasCompileFlag(cfg, '-faligned-allocation')),