diff --git a/CMakeLists.txt b/CMakeLists.txt
index b8a66a65..772fffb5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,6 +23,11 @@ option(BUILD_XDSP "Build XDSP math" OFF)
 
 option(BUILD_SHMATH "Build Spherical Harmonics math" OFF)
 
+string(TOLOWER "${CMAKE_SYSTEM_PROCESSOR}" DIRECTXMATH_SYSTEM_PROCESSOR_LOWER)
+if(DIRECTXMATH_SYSTEM_PROCESSOR_LOWER MATCHES "^riscv")
+  message(STATUS "RISC-V target detected; DirectXMath will use the scalar no-intrinsics backend")
+endif()
+
 include(GNUInstallDirs)
 
 #--- Library
diff --git a/Extensions/DirectXMathAVX.h b/Extensions/DirectXMathAVX.h
index 964a9a48..39a7386e 100644
--- a/Extensions/DirectXMathAVX.h
+++ b/Extensions/DirectXMathAVX.h
@@ -9,8 +9,8 @@
 
 #pragma once
 
-#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__
-#error AVX not supported on ARM platform
+#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__ || defined(__riscv)
+#error AVX not supported on this platform
 #endif
 
 #include <DirectXMath.h>
diff --git a/Extensions/DirectXMathAVX2.h b/Extensions/DirectXMathAVX2.h
index 3ee88065..9824bd32 100644
--- a/Extensions/DirectXMathAVX2.h
+++ b/Extensions/DirectXMathAVX2.h
@@ -9,8 +9,8 @@
 
 #pragma once
 
-#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__
-#error AVX2 not supported on ARM platform
+#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__ || defined(__riscv)
+#error AVX2 not supported on this platform
 #endif
 
 #include <DirectXMath.h>
diff --git a/Extensions/DirectXMathF16C.h b/Extensions/DirectXMathF16C.h
index cf0995d5..4c28e5c1 100644
--- a/Extensions/DirectXMathF16C.h
+++ b/Extensions/DirectXMathF16C.h
@@ -9,8 +9,8 @@
 
 #pragma once
 
-#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__
-#error F16C not supported on ARM platform
+#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__ || defined(__riscv)
+#error F16C not supported on this platform
 #endif
 
 #include <DirectXMath.h>
diff --git a/Extensions/DirectXMathFMA3.h b/Extensions/DirectXMathFMA3.h
index a991d3f8..616634cd 100644
--- a/Extensions/DirectXMathFMA3.h
+++ b/Extensions/DirectXMathFMA3.h
@@ -9,8 +9,8 @@
 
 #pragma once
 
-#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__
-#error FMA3 not supported on ARM platform
+#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__ || defined(__riscv)
+#error FMA3 not supported on this platform
 #endif
 
 #include <DirectXMath.h>
diff --git a/Extensions/DirectXMathFMA4.h b/Extensions/DirectXMathFMA4.h
index c6394faf..ceba2d9e 100644
--- a/Extensions/DirectXMathFMA4.h
+++ b/Extensions/DirectXMathFMA4.h
@@ -9,8 +9,8 @@
 
 #pragma once
 
-#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__
-#error FMA4 not supported on ARM platform
+#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__ || defined(__riscv)
+#error FMA4 not supported on this platform
 #endif
 
 #include <DirectXMath.h>
diff --git a/Extensions/DirectXMathSSE3.h b/Extensions/DirectXMathSSE3.h
index 667d1d91..58717c5f 100644
--- a/Extensions/DirectXMathSSE3.h
+++ b/Extensions/DirectXMathSSE3.h
@@ -9,8 +9,8 @@
 
 #pragma once
 
-#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__
-#error SSE3 not supported on ARM platform
+#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__ || defined(__riscv)
+#error SSE3 not supported on this platform
 #endif
 
 #include <pmmintrin.h>
diff --git a/Extensions/DirectXMathSSE4.h b/Extensions/DirectXMathSSE4.h
index c20eafd1..ad842c92 100644
--- a/Extensions/DirectXMathSSE4.h
+++ b/Extensions/DirectXMathSSE4.h
@@ -9,8 +9,8 @@
 
 #pragma once
 
-#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__
-#error SSE4 not supported on ARM platform
+#if defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__ || defined(__riscv)
+#error SSE4 not supported on this platform
 #endif
 
 #include <smmintrin.h>
diff --git a/Inc/DirectXMath.h b/Inc/DirectXMath.h
index bc7451fc..f672f43c 100644
--- a/Inc/DirectXMath.h
+++ b/Inc/DirectXMath.h
@@ -86,6 +86,9 @@
 #define _XM_SSE_INTRINSICS_
 #elif defined(_M_ARM) || defined(_M_ARM64) || defined(_M_HYBRID_X86_ARM64) || defined(_M_ARM64EC) || __arm__ || __aarch64__
 #define _XM_ARM_NEON_INTRINSICS_
+#elif defined(__riscv)
+// RISC-V currently uses the existing scalar no-intrinsics implementation.
+#define _XM_NO_INTRINSICS_
 #elif !defined(_XM_NO_INTRINSICS_)
 #error DirectX Math does not support this target
 #endif
diff --git a/README.md b/README.md
index 60cabff6..1093def9 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,8 @@ copilot
 
 Officially the library is supported with Microsoft Visual C++ 2019 (16.11) or later, clang/LLVM v12 or later, and GCC 10 or later. It should also compile with the Intel C++ and MinGW compilers.
 
+On `riscv64`, DirectXMath currently uses its existing scalar `_XM_NO_INTRINSICS_` backend. This provides a conservative portability path for the core headers, but it does not add any RISC-V vector or assembly implementation. The x86-specific extension headers under `Extensions/` remain unsupported there.
+
 When building with clang/LLVM or other GNU C compilers, the ``_XM_NO_XMVECTOR_OVERLOADS_`` control define is set because these compilers do not support creating operator overloads for the ``XMVECTOR`` type. You can choose to enable this preprocessor define explicitly to do the same thing with Visual C++ for improved portability.
 
 To build for non-Windows platforms, you need to provide a ``sal.h`` header in your include path. You can obtain an open source version from [GitHub](https://raw.githubusercontent.com/dotnet/runtime/main/src/coreclr/pal/inc/rt/sal.h).