diff --git a/pkgs/development/python-modules/flax/default.nix b/pkgs/development/python-modules/flax/default.nix
new file mode 100644
index 0000000000000..b8479c0f73cad
--- /dev/null
+++ b/pkgs/development/python-modules/flax/default.nix
@@ -0,0 +1,60 @@
+{ buildPythonPackage
+, fetchFromGitHub
+, keras
+, lib
+, matplotlib
+, msgpack
+, numpy
+, optax
+, pytestCheckHook
+, tensorflow
+}:
+
+buildPythonPackage rec {
+  pname = "flax";
+  version = "0.3.6";
+
+  src = fetchFromGitHub {
+    owner = "google";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "0zvq0vl88hiwmss49bnm7gdmndr1dfza2bcs1fj88a9r7w9dmlsr";
+  };
+
+  propagatedBuildInputs = [
+    matplotlib
+    msgpack
+    numpy
+    optax
+  ];
+
+  pythonImportsCheck = [
+    "flax"
+  ];
+
+  checkInputs = [
+    keras
+    pytestCheckHook
+    tensorflow
+  ];
+
+  disabledTestPaths = [
+    # Docs test, needs extra deps + we're not interested in it.
+    "docs/_ext/codediff_test.py"
+
+    # The tests in `examples` are not designed to be executed from a single test
+    # session and thus either have the modules that conflict with each other or
+    # wrong import paths, depending on how they're invoked. Many tests also have
+    # dependencies that are not packaged in `nixpkgs` (`clu`, `jgraph`,
+    # `tensorflow_datasets`, `vocabulary`) so the benefits of trying to run them
+    # would be limited anyway.
+    "examples/*"
+  ];
+
+  meta = with lib; {
+    description = "Neural network library for JAX";
+    homepage = "https://github.com/google/flax";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ ndl ];
+  };
+}
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index e2d2b193f8640..9f2aa79b220f5 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -2945,6 +2945,8 @@ in {
     inherit (pkgs) flatbuffers;
   };
 
+  flax = callPackage ../development/python-modules/flax { };
+
   flexmock = callPackage ../development/python-modules/flexmock { };
 
   flickrapi = callPackage ../development/python-modules/flickrapi { };