diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e944eae23bc..eb7d4ed36ba 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -34,7 +34,6 @@ jobs:
   build:
     continue-on-error: ${{ endsWith(inputs.python-version, '-dev') || contains(fromJSON('["beta", "nightly"]'), inputs.rust) }}
     runs-on: ${{ inputs.os }}
-    if: ${{ !(startsWith(inputs.python-version, 'graalpy') && startsWith(inputs.os, 'windows')) }}
     steps:
       - uses: actions/checkout@v7.0.1
         with:
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 52c2e98628c..cea49a9ba93 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -297,7 +297,8 @@ jobs:
             "3.15-dev",
             "3.15t-dev",
             "pypy3.11",
-            "graalpy25.0",
+            "graalpy25.2", # 3.12
+            "graalpy25.3", # 3.13
           ]
         platform:
           [
diff --git a/Cargo.toml b/Cargo.toml
index 52bc2c414f6..6097df53f75 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -255,7 +255,7 @@ check-cfg = [
     #
     # maybe in the future this list will not be necessary, see
     # internals.rust-lang.org/t/support-renames-with-link-name-kind-raw-dylib/24415
-    'cfg(pyo3_dll, values("python3", "python3_d", "python3t", "python3t_d", "python38", "python38_d", "python39", "python39_d", "python310", "python310_d", "python311", "python311_d", "python312", "python312_d", "python313", "python313_d", "python313t", "python313t_d", "python314", "python314_d", "python314t", "python314t_d", "python315", "python315_d", "python315t", "python315t_d", "python316", "python316_d", "python316t", "python316t_d", "libpypy3.11-c", "libpypy3.12-c"))',
+    'cfg(pyo3_dll, values("python3", "python3_d", "python3t", "python3t_d", "python38", "python38_d", "python39", "python39_d", "python310", "python310_d", "python311", "python311_d", "python312", "python312_d", "python313", "python313_d", "python313t", "python313t_d", "python314", "python314_d", "python314t", "python314t_d", "python315", "python315_d", "python315t", "python315t_d", "python316", "python316_d", "python316t", "python316t_d", "libpypy3.11-c", "libpypy3.12-c", "python-native"))',
 ]
 
 
diff --git a/newsfragments/6406.packaging.md b/newsfragments/6406.packaging.md
new file mode 100644
index 00000000000..e6e1fcbd23a
--- /dev/null
+++ b/newsfragments/6406.packaging.md
@@ -0,0 +1 @@
+Support GraalPy on Windows.
diff --git a/noxfile.py b/noxfile.py
index a0aaf4505c2..2aa9d573af5 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -1494,6 +1494,9 @@ def _check_raw_dylib_macro(session: nox.Session):
     ):
         expected_dlls.add(f"libpypy3.{minor}-c")
 
+    # GraalPy DLL (python-native.dll)
+    expected_dlls.add("python-native")
+
     # Parse the DLL name list in the extern_libpython!(@impl ...) invocation
     lib_rs = (PYO3_DIR / "pyo3-ffi" / "src" / "impl_" / "macros.rs").read_text()
     found_dlls = set(re.findall(r'"((?:python(?!XY)|libpypy)[^"]+)"', lib_rs))
diff --git a/pyo3-build-config/src/impl_.rs b/pyo3-build-config/src/impl_.rs
index 2c63cd724cc..8272c6582e5 100644
--- a/pyo3-build-config/src/impl_.rs
+++ b/pyo3-build-config/src/impl_.rs
@@ -2396,15 +2396,6 @@ fn default_lib_name_for_target(abi: PythonAbi, target: &Triple) -> String {
 }
 
 fn default_lib_name_windows(abi: PythonAbi, mingw: bool, debug: bool) -> Result<String> {
-    // mingw formats lib names like unix, and uses a "lib" prefix. We could let the linker
-    // handle "lib" prefix, but that means the `raw-dylib` name is incorrect (where the
-    // "lib" prefix is not automatically added).
-    if mingw {
-        let mut lib_name = default_lib_name_unix(abi, true, None)?;
-        lib_name.insert_str(0, "lib");
-        return Ok(lib_name);
-    }
-
     if abi.implementation.is_pypy() {
         // PyPy on Windows ships `libpypy3.X-c.dll` (e.g. `libpypy3.11-c.dll`),
         // not CPython's `pythonXY.dll`. With raw-dylib linking we need the real
@@ -2413,6 +2404,16 @@ fn default_lib_name_windows(abi: PythonAbi, mingw: bool, debug: bool) -> Result<
             "libpypy{}.{}-c",
             abi.version.major, abi.version.minor
         ))
+    } else if abi.implementation == PythonImplementation::GraalPy {
+        // Similar for GraalPy on Windows, which ships `python-native.dll`
+        Ok("python-native".to_string())
+    } else if mingw {
+        // mingw formats lib names like unix, and uses a "lib" prefix. We could let the linker
+        // handle "lib" prefix, but that means the `raw-dylib` name is incorrect (where the
+        // "lib" prefix is not automatically added).
+        let mut lib_name = default_lib_name_unix(abi, true, None)?;
+        lib_name.insert_str(0, "lib");
+        Ok(lib_name)
     } else if debug && abi.version < PythonVersion::PY310 {
         // CPython bug: linking against python3_d.dll raises error
         // https://github.com/python/cpython/issues/101614
diff --git a/pyo3-ffi-check/definitions/wrapper.h b/pyo3-ffi-check/definitions/wrapper.h
index 2c822162b6b..b3128dc8c27 100644
--- a/pyo3-ffi-check/definitions/wrapper.h
+++ b/pyo3-ffi-check/definitions/wrapper.h
@@ -2,4 +2,8 @@
 #include "datetime.h"
 #include "frameobject.h"
 #include "structmember.h"
+
+// no marshal.h in GraalPy
+#ifndef GRAALVM_PYTHON
 #include "marshal.h"
+#endif
diff --git a/pyo3-ffi-check/macro/src/lib.rs b/pyo3-ffi-check/macro/src/lib.rs
index 0d3afcac282..90f19f4b1d3 100644
--- a/pyo3-ffi-check/macro/src/lib.rs
+++ b/pyo3-ffi-check/macro/src/lib.rs
@@ -56,6 +56,13 @@ pub fn for_all_structs(input: proc_macro::TokenStream) -> proc_macro::TokenStrea
             continue;
         }
 
+        if pyo3_build_config::get().target_abi().implementation() == PythonImplementation::GraalPy
+            && (struct_name == "PyFunctionObject" || struct_name == "PySliceObject")
+        {
+            // GraalPy wants these types to be opaque, we skip them
+            continue;
+        }
+
         let struct_ident = Ident::new(struct_name, Span::call_site());
         output.extend(quote!(#macro_name!(#struct_ident);));
     }
@@ -263,6 +270,17 @@ pub fn for_all_fields(input: proc_macro::TokenStream) -> proc_macro::TokenStream
         // bindgen picked `__bindgen_anon_1` as the field name for the anonymous union containing ob_refcnt,
         // PyO3 uses ob_refcnt directly
         all_fields.remove("__bindgen_anon_1");
+    } else if struct_name == "PyVarObject"
+        && pyo3_build_config::get().target_abi().implementation() == PythonImplementation::GraalPy
+    {
+        // ob_size not present in GraalPy
+        all_fields.remove("ob_size");
+    } else if pyo3_build_config::get().target_abi().implementation()
+        == PythonImplementation::GraalPy
+        && (struct_name == "PyFunctionObject" || struct_name == "PySliceObject")
+    {
+        // GraalPy wants these types to be opaque, we skip them
+        return TokenStream::new().into();
     }
 
     let mut output = TokenStream::new();
@@ -533,7 +551,7 @@ const MACRO_EXCLUSIONS: &[(&str, &str)] = &[
     ("Py_IS_TYPE", "not(Py_3_15)"), // symbol added for stable abi on 3.15
     ("Py_None", ""),
     ("Py_NotImplemented", ""),
-    ("Py_REFCNT", "not(Py_3_14)"),
+    ("Py_REFCNT", "all(not(Py_3_14), not(GraalPy))"),
     ("Py_SIZE", "not(Py_3_15)"), // symbol added for stable abi on 3.15
     ("Py_True", ""),
     ("Py_TYPE", "not(Py_3_14)"),
diff --git a/pyo3-ffi/build.rs b/pyo3-ffi/build.rs
index 70e193d2cae..860d9055eb1 100644
--- a/pyo3-ffi/build.rs
+++ b/pyo3-ffi/build.rs
@@ -195,10 +195,12 @@ fn ensure_target_pointer_width(interpreter_config: &InterpreterConfig) -> Result
 /// (see https://internals.rust-lang.org/t/support-renames-with-link-name-kind-raw-dylib/24415)
 /// so if the lib name is not one of the known subset, we must fall back to full linking.
 fn lib_name_is_known_for_raw_dylib(lib_name: &str) -> bool {
-    // pyo3_dll cfg for raw-dylib linking on Windows
     if matches!(
         lib_name,
+        // pyo3_dll cfg for raw-dylib linking on Windows
         "python3" | "python3_d" | "python3t" | "python3t_d"
+        // GraalPy DLL name
+        | "python-native"
     ) {
         return true;
     }
diff --git a/pyo3-ffi/src/cpython/mod.rs b/pyo3-ffi/src/cpython/mod.rs
index 5303a57f59d..f44de934614 100644
--- a/pyo3-ffi/src/cpython/mod.rs
+++ b/pyo3-ffi/src/cpython/mod.rs
@@ -26,6 +26,7 @@ pub(crate) mod listobject;
 #[cfg(Py_3_13)]
 pub(crate) mod lock;
 pub(crate) mod longobject;
+#[cfg(not(GraalPy))]
 pub(crate) mod marshal;
 #[cfg(not(PyPy))]
 pub(crate) mod methodobject;
@@ -77,6 +78,7 @@ pub use self::listobject::*;
 #[cfg(Py_3_13)]
 pub use self::lock::*;
 pub use self::longobject::*;
+#[cfg(not(GraalPy))]
 pub use self::marshal::*;
 #[cfg(not(PyPy))]
 pub use self::methodobject::*;
diff --git a/pyo3-ffi/src/datetime.rs b/pyo3-ffi/src/datetime.rs
index d2022138a87..f4b6a9bd81b 100644
--- a/pyo3-ffi/src/datetime.rs
+++ b/pyo3-ffi/src/datetime.rs
@@ -350,7 +350,7 @@ pub unsafe fn PyDateTime_DELTA_GET_MICROSECONDS(o: *mut PyObject) -> c_int {
 // but copying them seems suboptimal
 #[inline]
 #[cfg(GraalPy)]
-pub unsafe fn _get_attr(obj: *mut PyObject, field: &core::ffi::CStr) -> c_int {
+unsafe fn _get_attr(obj: *mut PyObject, field: &core::ffi::CStr) -> c_int {
     let result = PyObject_GetAttrString(obj, field.as_ptr());
     Py_DecRef(result); // the original macros are borrowing
     if PyLong_Check(result) == 1 {
diff --git a/pyo3-ffi/src/impl_/macros.rs b/pyo3-ffi/src/impl_/macros.rs
index 5ca4a4ac3bc..49099f9e147 100644
--- a/pyo3-ffi/src/impl_/macros.rs
+++ b/pyo3-ffi/src/impl_/macros.rs
@@ -289,6 +289,8 @@ macro_rules! extern_libpython {
             // PyPy (DLL is libpypy3.X-c.dll, not pythonXY.dll)
             "libpypy3.11-c",
             "libpypy3.12-c",
+            // GraalPy DLL
+            "python-native",
         );
     };
     // Internal: generate cfg_attr for each DLL name. One of these will be selected
diff --git a/pyo3-ffi/src/object.rs b/pyo3-ffi/src/object.rs
index 40578b244d1..91a146c537f 100644
--- a/pyo3-ffi/src/object.rs
+++ b/pyo3-ffi/src/object.rs
@@ -169,7 +169,7 @@ pub struct PyVarObject {
     pub ob_size: Py_ssize_t,
     // On GraalPy the field is physically there, but not always populated. We hide it to prevent accidental misuse
     #[cfg(GraalPy)]
-    pub _ob_size_graalpy: Py_ssize_t,
+    _ob_size_graalpy: Py_ssize_t,
 }
 
 #[inline]
diff --git a/src/marshal.rs b/src/marshal.rs
index 56249492a06..4ee15fa9a34 100644
--- a/src/marshal.rs
+++ b/src/marshal.rs
@@ -1,4 +1,4 @@
-#![cfg(not(Py_LIMITED_API))]
+#![cfg(not(any(Py_LIMITED_API, GraalPy)))]
 
 //! Support for the Python `marshal` format.