diff --git a/pkgs/tools/games/pokefinder/cstddef.patch b/pkgs/tools/games/pokefinder/cstddef.patch
new file mode 100644
index 000000000000..c74340b0d6df
--- /dev/null
+++ b/pkgs/tools/games/pokefinder/cstddef.patch
@@ -0,0 +1,12 @@
+diff --git a/Source/Core/Util/EncounterSlot.cpp b/Source/Core/Util/EncounterSlot.cpp
+index adddbdab..71c98e83 100644
+--- a/Source/Core/Util/EncounterSlot.cpp
++++ b/Source/Core/Util/EncounterSlot.cpp
+@@ -20,6 +20,7 @@
+ #include "EncounterSlot.hpp"
+ #include <Core/Enum/Encounter.hpp>
+ #include <array>
++#include <cstddef>
+ 
+ namespace
+ {
diff --git a/pkgs/tools/games/pokefinder/default.nix b/pkgs/tools/games/pokefinder/default.nix
new file mode 100644
index 000000000000..547b0c47bc26
--- /dev/null
+++ b/pkgs/tools/games/pokefinder/default.nix
@@ -0,0 +1,46 @@
+{ lib
+, stdenv
+, fetchFromGitHub
+, cmake
+, qtbase
+, qttools
+, wrapQtAppsHook
+, gitUpdater
+}:
+
+stdenv.mkDerivation rec {
+  pname = "pokefinder";
+  version = "4.0.1";
+
+  src = fetchFromGitHub {
+    owner = "Admiral-Fish";
+    repo = "PokeFinder";
+    rev = "v${version}";
+    sha256 = "j7xgjNF8NWLFVPNItWcFM5WL8yPxgHxVX00x7lt45WI=";
+    fetchSubmodules = true;
+  };
+
+  patches = [ ./cstddef.patch ];
+
+  postPatch = ''
+    patchShebangs Source/Core/Resources/
+  '';
+
+  installPhase = ''
+    install -D Source/Forms/PokeFinder $out/bin/PokeFinder
+  '';
+
+  nativeBuildInputs = [ cmake wrapQtAppsHook ];
+
+  buildInputs = [ qtbase qttools ];
+
+  passthru.updateScript = gitUpdater { };
+
+  meta = with lib; {
+    homepage = "https://github.com/Admiral-Fish/PokeFinder";
+    description = "Cross platform Pokémon RNG tool";
+    license = licenses.gpl3Only;
+    platforms = platforms.all;
+    maintainers = with maintainers; [ leo60228 ];
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index f7a1949c7b5f..441be9ae33ea 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -31419,6 +31419,8 @@ with pkgs;
 
   poke = callPackage ../applications/editors/poke { };
 
+  pokefinder = qt6Packages.callPackage ../tools/games/pokefinder { };
+
   pokemonsay = callPackage ../tools/misc/pokemonsay { };
 
   polar-bookshelf = callPackage ../applications/misc/polar-bookshelf { };