--- a/premake5.lua
+++ b/premake5.lua
@@ -18,6 +18,18 @@ objdir(build_obj)
 enableTests = false
 enableMiscSubprojects = false
 
+-- USE_SYSTEM_XXHASH: use system libxxhash when set (Linux only). Fail if set and not found.
+use_system_xxhash = false
+if os.istarget("linux") then
+  local env = os.getenv("USE_SYSTEM_XXHASH") or ""
+  if env ~= "" and env ~= "0" then
+    use_system_xxhash = true
+    if not os.execute("pkg-config --exists libxxhash") then
+      error("USE_SYSTEM_XXHASH is set but libxxhash was not found. Install dev-libs/xxhash or unset USE_SYSTEM_XXHASH.")
+    end
+  end
+end
+
 -- Define an ARCH variable
 -- Only use this to enable architecture-specific functionality.
 if os.istarget("linux") then
@@ -40,6 +52,9 @@ defines({
   --"IMGUI_ENABLE_FREETYPE",
   "USE_CPP17", -- Tabulate
 })
+if use_system_xxhash then
+  defines({ "XENIA_USE_SYSTEM_XXHASH" })
+end
 
 cdialect("C17")
 cppdialect("C++20")
@@ -314,7 +329,9 @@ workspace("xenia")
   include("third_party/imgui.lua")
   include("third_party/mspack.lua")
   include("third_party/snappy.lua")
-  include("third_party/xxhash.lua")
+  if not use_system_xxhash then
+    include("third_party/xxhash.lua")
+  end
   include("third_party/zarchive.lua")
   include("third_party/zstd.lua")
   include("third_party/zlib-ng.lua")
--- a/src/xenia/app/premake5.lua
+++ b/src/xenia/app/premake5.lua
@@ -5,6 +5,9 @@ group("src")
 project("xenia-app")
   uuid("d7e98620-d007-4ad8-9dbd-b47c8853a17f")
   language("C++")
+  if use_system_xxhash then
+    pkg_config.all("libxxhash")
+  end
   links({
     "xenia-apu",
     "xenia-apu-nop",
--- a/src/xenia/base/xxhash.h
+++ b/src/xenia/base/xxhash.h
@@ -10,12 +10,18 @@
 #ifndef XENIA_BASE_XXHASH_H_
 #define XENIA_BASE_XXHASH_H_
 
+#ifdef XENIA_USE_SYSTEM_XXHASH
+/* Expose XXH3_state_s definition so stack-allocated XXH3_state_t is valid. */
+#define XXH_STATIC_LINKING_ONLY
+#include <xxhash.h>
+#else
 #define XXH_INLINE_ALL
 
 // Can't use XXH_X86DISPATCH because XXH is calculated on multiple threads,
 // while the dispatch writes the result (multiple pointers without any
 // synchronization) to XXH_g_dispatch at the first call.
 
 #include "third_party/xxhash/xxhash.h"
+#endif
 
 #endif  // XENIA_BASE_XXHASH_H_
--- a/src/xenia/gpu/d3d12/premake5.lua
+++ b/src/xenia/gpu/d3d12/premake5.lua
@@ -6,6 +6,9 @@ project("xenia-gpu-d3d12")
   uuid("c057eae4-e7bb-4113-9a69-1fe07b735c49")
   kind("StaticLib")
   language("C++")
+  if use_system_xxhash then
+    pkg_config.all("libxxhash")
+  end
   links({
     "fmt",
     "xenia-base",
@@ -25,6 +28,9 @@ if enableMiscSubprojects then
     uuid("7b5b9fcb-7bf1-43ff-a774-d4c41c8706be")
     single_library_windowed_app_kind()
     language("C++")
+    if use_system_xxhash then
+      pkg_config.all("libxxhash")
+    end
     links({
       "xenia-apu",
       "xenia-apu-nop",
--- a/src/xenia/gpu/null/premake5.lua
+++ b/src/xenia/gpu/null/premake5.lua
@@ -6,6 +6,9 @@ project("xenia-gpu-null")
   uuid("42FCA0B3-4C20-4532-95E9-07D297013BE4")
   kind("StaticLib")
   language("C++")
+  if use_system_xxhash then
+    pkg_config.all("libxxhash")
+  end
   links({
     "xenia-base",
     "xenia-gpu",
--- a/src/xenia/gpu/premake5.lua
+++ b/src/xenia/gpu/premake5.lua
@@ -6,6 +6,9 @@ project("xenia-gpu")
   uuid("0e8d3370-e4b1-4b05-a2e8-39ebbcdf9b17")
   kind("StaticLib")
   language("C++")
+  if use_system_xxhash then
+    pkg_config.all("libxxhash")
+  end
   links({
     "dxbc",
     "fmt",
--- a/src/xenia/gpu/vulkan/premake5.lua
+++ b/src/xenia/gpu/vulkan/premake5.lua
@@ -6,6 +6,9 @@ project("xenia-gpu-vulkan")
   uuid("717590b4-f579-4162-8f23-0624e87d6cca")
   kind("StaticLib")
   language("C++")
+  if use_system_xxhash then
+    pkg_config.all("libxxhash")
+  end
   links({
     "fmt",
     "glslang-spirv",
@@ -29,6 +32,9 @@ if enableMiscSubprojects then
     uuid("86a1dddc-a26a-4885-8c55-cf745225d93e")
     single_library_windowed_app_kind()
     language("C++")
+    if use_system_xxhash then
+      pkg_config.all("libxxhash")
+    end
     links({
       "xenia-apu",
       "xenia-apu-nop",