diff --git a/pkgs/development/ocaml-modules/jsont/default.nix b/pkgs/development/ocaml-modules/jsont/default.nix
new file mode 100644
index 000000000000..9703155b11f7
--- /dev/null
+++ b/pkgs/development/ocaml-modules/jsont/default.nix
@@ -0,0 +1,54 @@
+{
+  lib,
+  fetchzip,
+  buildTopkgPackage,
+  brr,
+  bytesrw,
+  cmdliner,
+}:
+
+buildTopkgPackage rec {
+  pname = "jsont";
+  version = "0.1.1";
+
+  minimalOCamlVersion = "4.14.0";
+
+  src = fetchzip {
+    url = "https://erratique.ch/software/jsont/releases/jsont-${version}.tbz";
+    hash = "sha256-bLbTfRVz/Jzuy2LnQeTEHQGojfA34M+Xj7LODpBAVK4=";
+  };
+
+  # docs say these dependendencies are optional, but buildTopkgPackage doesn’t
+  # handle missing dependencies
+
+  buildInputs = [
+    cmdliner
+  ];
+
+  propagatedBuildInputs = [
+    brr
+    bytesrw
+  ];
+
+  meta = {
+    description = "declarative JSON data manipulation";
+    longDescription = ''
+      Jsont is an OCaml library for declarative JSON data manipulation. it
+      provides:
+
+      • Combinators for describing JSON data using the OCaml values of your
+        choice. The descriptions can be used by generic functions to decode,
+        encode, query and update JSON data without having to construct a
+        generic JSON representation
+      • A JSON codec with optional text location tracking and best-effort
+        layout preservation. The codec is compatible with effect-based
+        concurrency.
+
+      The descriptions are independent from the codec and can be used by
+      third-party processors or codecs.
+    '';
+    homepage = "https://erratique.ch/software/jsont";
+    license = lib.licenses.isc;
+    maintainers = with lib.maintainers; [ toastal ];
+  };
+}
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index ba1c955db65b..bfbeb855256d 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -952,6 +952,8 @@ let
 
         jsonm = callPackage ../development/ocaml-modules/jsonm { };
 
+        jsont = callPackage ../development/ocaml-modules/jsont { };
+
         jsonrpc = callPackage ../development/ocaml-modules/ocaml-lsp/jsonrpc.nix { };
 
         junit = callPackage ../development/ocaml-modules/junit { };