diff --git a/pkgs/data/themes/omni-gtk-theme/default.nix b/pkgs/data/themes/omni-gtk-theme/default.nix
new file mode 100644
index 000000000000..b216eff6193a
--- /dev/null
+++ b/pkgs/data/themes/omni-gtk-theme/default.nix
@@ -0,0 +1,34 @@
+{ lib, stdenv, fetchFromGitHub, gtk-engine-murrine }:
+
+stdenv.mkDerivation {
+  pname = "omni-gtk-theme";
+  version = "unstable-2021-03-30";
+
+  src = fetchFromGitHub {
+    owner = "getomni";
+    repo = "gtk";
+    rev = "e81b3fbebebf53369cffe1fb662abc400edb04f7";
+    sha256 = "sha256-NSZjkG+rY6h8d7FYq5kipPAjMDAgyaYAgOOOJlfqBCI=";
+  };
+
+  propagatedUserEnvPkgs = [
+    gtk-engine-murrine
+  ];
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/share/themes/Omni
+    cp -a {assets,gnome-shell,gtk-2.0,gtk-3.0,gtk-3.20,index.theme,metacity-1,unity,xfwm4} $out/share/themes/Omni
+
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "Dark theme created by Rocketseat";
+    homepage = "https://github.com/getomni/gtk";
+    license = licenses.gpl3;
+    platforms = platforms.all;
+    maintainers = with maintainers; [ zoedsoupe ];
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 46efeea98205..0b6182fabfa0 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -25341,6 +25341,8 @@ with pkgs;
 
   oldsindhi = callPackage ../data/fonts/oldsindhi { };
 
+  omni-gtk-theme = callPackage ../data/themes/omni-gtk-theme { };
+
   onestepback = callPackage ../data/themes/onestepback { };
 
   open-dyslexic = callPackage ../data/fonts/open-dyslexic { };