diff --git a/pkgs/applications/science/astronomy/siril/default.nix b/pkgs/applications/science/astronomy/siril/default.nix
new file mode 100644
index 00000000000..7ae3e011973
--- /dev/null
+++ b/pkgs/applications/science/astronomy/siril/default.nix
@@ -0,0 +1,45 @@
+{ stdenv, fetchFromGitLab, fetchFromGitHub, pkg-config, meson, ninja,
+  git, criterion, wrapGAppsHook, gtk3, libconfig, gnuplot, opencv,
+  fftwFloat, cfitsio, gsl, exiv2, curl, librtprocess, ffmpeg,
+  libraw, libtiff, libpng, libjpeg, libheif, ffms
+}:
+
+stdenv.mkDerivation rec {
+  pname = "siril";
+  version = "0.99.6";
+
+  src = fetchFromGitLab {
+    owner = "free-astro";
+    repo = pname;
+    rev = version;
+    sha256 = "06vh8x45gv0gwlnqjwxglf12jmpdaxkiv5sixkqh20420wabx3ha";
+  };
+
+  nativeBuildInputs = [
+    meson ninja pkg-config git criterion wrapGAppsHook
+  ];
+
+  buildInputs = [
+    gtk3 cfitsio gsl exiv2 gnuplot curl opencv fftwFloat librtprocess
+    libconfig libraw libtiff libpng libjpeg libheif ffms ffmpeg
+  ];
+
+  # Necessary because project uses default build dir for flatpaks/snaps
+  dontUseMesonConfigure = true;
+
+  configureScript = ''
+    ${meson}/bin/meson --buildtype release nixbld .
+  '';
+
+  postConfigure = ''
+    cd nixbld
+  '';
+
+  meta = with stdenv.lib; {
+    homepage = "https://www.siril.org/";
+    description = "Astronomical image processing tool";
+    license = licenses.gpl3;
+    maintainers = with maintainers; [ hjones2199 ];
+    platforms = [ "x86_64-linux" ];
+  };
+}
diff --git a/pkgs/development/libraries/librtprocess/default.nix b/pkgs/development/libraries/librtprocess/default.nix
new file mode 100644
index 00000000000..adabbe11cb3
--- /dev/null
+++ b/pkgs/development/libraries/librtprocess/default.nix
@@ -0,0 +1,23 @@
+{ stdenv, fetchFromGitHub, cmake }:
+
+stdenv.mkDerivation rec {
+  pname = "librtprocess";
+  version = "0.11.0";
+
+  src = fetchFromGitHub {
+    owner = "CarVac";
+    repo = pname;
+    rev = version;
+    sha256 = "1bivy3rymmmkdx5phbxq4qaq15hw633dgpks57z9ara15mh817xx";
+  };
+
+  nativeBuildInputs = [ cmake ];
+
+  meta = with stdenv.lib; {
+    homepage = "https://github.com/CarVac/librtprocess";
+    description = "Highly optimized library for processing RAW images";
+    license = licenses.gpl3;
+    maintainers = with maintainers; [ hjones2199 ];
+    platforms = [ "x86_64-linux" ];
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 7573e22c91e..d2185df3897 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -7289,6 +7289,8 @@ in
 
   sipsak = callPackage ../tools/networking/sipsak { };
 
+  siril = callPackage ../applications/science/astronomy/siril { };
+
   sisco.lv2 = callPackage ../applications/audio/sisco.lv2 { };
 
   sit = callPackage ../applications/version-management/sit {
@@ -14276,6 +14278,8 @@ in
 
   librime = callPackage ../development/libraries/librime {};
 
+  librtprocess = callPackage ../development/libraries/librtprocess { };
+
   libsamplerate = callPackage ../development/libraries/libsamplerate {
     inherit (darwin.apple_sdk.frameworks) ApplicationServices Carbon CoreServices;
   };