diff --git a/var/spack/repos/builtin/packages/greenx/package.py b/var/spack/repos/builtin/packages/greenx/package.py
new file mode 100644
index 00000000000..7f28ef071d0
--- /dev/null
+++ b/var/spack/repos/builtin/packages/greenx/package.py
@@ -0,0 +1,50 @@
+# Copyright Spack Project Developers. See COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack.package import *
+
+
+class Greenx(CMakePackage):
+    """GreenX: An open-source library that supports exascale implementations
+    of Green's-function-based methodologies."""
+
+    homepage = "https://nomad-coe.github.io/greenX"
+    url = "https://github.com/nomad-coe/greenX/archive/refs/tags/v2.1.tar.gz"
+
+    maintainers("RMeli")
+
+    license("Apache-2.0", checked_by="RMeli")
+
+    version("2.1", sha256="2fc1fc2c93b0bab14babc33386f7932192336813cea6db11cd27dbc36b541e41")
+
+    variant("shared", default=True, description="Build shared libraries")
+    variant("ac", default=True, description="Enable Analytical Continuation component")
+    variant(
+        "gmp",
+        when="+ac",
+        default=True,
+        description="Enable GMP library for multiple precision arithmetic",
+    )
+    variant("minmax", default=True, description="Enable minmax time-frequency grids component")
+    variant("lbasis", default=False, description="Enable localized basis component")
+    variant("paw", default=False, description="Enable PAW component")
+
+    depends_on("cxx", type="build")
+    depends_on("fortran", type="build")
+
+    depends_on("blas")
+    depends_on("lapack")
+
+    depends_on("gmp", when="+gmp")
+
+    def cmake_args(self):
+        args = [
+            self.define_from_variant("BUILD_SHARED_LIBS", "shared"),
+            self.define_from_variant("AC_COMPONENT", "ac"),
+            self.define_from_variant("ENABLE_GNU_GMP", "gmp"),
+            self.define_from_variant("MINMAX_COMPONENT", "minmax"),
+            self.define_from_variant("LBASIS_COMPONENT", "lbasis"),
+            self.define_from_variant("PAW_COMPONENT", "paw"),
+        ]
+        return args