diff --git a/pkgs/development/ocaml-modules/tw/default.nix b/pkgs/development/ocaml-modules/tw/default.nix
new file mode 100644
index 000000000000..55f73dbe105c
--- /dev/null
+++ b/pkgs/development/ocaml-modules/tw/default.nix
@@ -0,0 +1,55 @@
+{
+  buildDunePackage,
+  cascade,
+  cmdliner,
+  fetchFromGitHub,
+  fmt,
+  lib,
+  ocaml,
+}:
+
+buildDunePackage (finalAttrs: {
+  pname = "tw";
+  version = "0-unstable-2026-06-23";
+  minimalOCamlVersion = "5.2";
+  __structuredAttrs = true;
+
+  src = fetchFromGitHub {
+    owner = "samoht";
+    repo = "tw";
+    rev = "594d35df46ec2afcfe97632923331badf2940b93";
+    hash = "sha256-vCRq0FCBIxc/AQg+R2Hig7nqwJGxgy2jedLbAsKaIoA=";
+  };
+
+  propagatedBuildInputs = [ cascade ];
+  buildInputs = [
+    cmdliner
+    fmt
+  ];
+
+  # Disabling tests because they check for byte-for-byte identical
+  # output with tailwindcss, so they are tied to a specific
+  # tailwindcss version, and would prevent independent upgrades of tw
+  # and tailwindcss.
+  doCheck = false;
+
+  outputs = [
+    "bin"
+    "lib"
+    "out"
+  ];
+
+  installPhase = ''
+    runHook preInstall
+    dune install --prefix=$bin --libdir=$lib/lib/ocaml/${ocaml.version}/site-lib
+    runHook postInstall
+  '';
+
+  meta = {
+    description = "Type-safe Tailwind CSS v4 in OCaml";
+    homepage = "https://github.com/samoht/tw";
+    mainProgram = "tw";
+    license = lib.licenses.isc;
+    maintainers = [ lib.maintainers.vog ];
+  };
+})
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 5b1e4c87fc3a..287d06540253 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1213,6 +1213,8 @@ with pkgs;
     )
   );
 
+  tw = ocamlPackages.tw.bin;
+
   wrapRetroArch = retroarch-bare.wrapper;
 
   # Aliases kept here because they are easier to use
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index 4f5e425673bf..974759c5491b 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -2191,6 +2191,8 @@ let
 
         tuntap = callPackage ../development/ocaml-modules/tuntap { };
 
+        tw = callPackage ../development/ocaml-modules/tw { };
+
         twt = callPackage ../development/ocaml-modules/twt { };
 
         type_eq = callPackage ../development/ocaml-modules/type_eq { };