diff --git a/pkgs/by-name/fc/fcitx5-mellow-themes/package.nix b/pkgs/by-name/fc/fcitx5-mellow-themes/package.nix
new file mode 100644
index 000000000000..736bcac619b5
--- /dev/null
+++ b/pkgs/by-name/fc/fcitx5-mellow-themes/package.nix
@@ -0,0 +1,41 @@
+{
+  lib,
+  stdenvNoCC,
+  fetchFromGitHub,
+  jdupes,
+}:
+
+stdenvNoCC.mkDerivation {
+  pname = "fcitx5-mellow-themes";
+  version = "0-unstable-2024-11-11";
+
+  src = fetchFromGitHub {
+    owner = "sanweiya";
+    repo = "fcitx5-mellow-themes";
+    rev = "9694953eb1bd6c9363cf9c76833347bfa5ffd886";
+    hash = "sha256-+wJOPUmUkR/uR9zdFyrV86D6nsYnC94zHXkEfjmAVjs=";
+  };
+
+  nativeBuildInputs = [ jdupes ];
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/share/fcitx5/themes
+    cp -r *mellow* $out/share/fcitx5/themes
+    jdupes --quiet --link-soft --recurse $out/share
+
+    runHook postInstall
+  '';
+
+  meta = {
+    description = "Aesthetic, modern fcitx5 theme featuring rounded rectangle design";
+    homepage = "https://github.com/sanweiya/fcitx5-mellow-themes";
+    license = lib.licenses.bsd2;
+    platforms = lib.platforms.all;
+    maintainers = with lib.maintainers; [
+      Guanran928
+      zendo
+    ];
+  };
+}