diff --git a/games-engines/openmw/Manifest b/games-engines/openmw/Manifest
index 8df11082de73b..9147a89755bc1 100644
--- a/games-engines/openmw/Manifest
+++ b/games-engines/openmw/Manifest
@@ -1,2 +1,3 @@
 DIST openmw-0.50.0.tar.gz 6244084 BLAKE2B b2354d3e6328db54d4ddad9d7805d6af0c3dcf480e1ee24a37100389c1ab5c2a509692a0dfd0863c27e306e60cf35e5baf3d2db325b152ef7f28f8ac7fc5b072 SHA512 9221a3825da265b2145b7cf4a5f197b52ac890e27e0c303358b92c7030e92787d039afb4f66bde39304937bd9f9f00e4f66b10c07abf108eabbd818aab3a513b
+DIST openmw-0.51.0.tar.gz 6325148 BLAKE2B 828a0c5663bee6ffafdabbe521d8400f7f28a1732ab922ddb9fbd78591a4549b48fdb556e2fb02e54a4695370855adb77fe21b78e64582fb7ad561a2886ca377 SHA512 a993896fe3f9e0c3c4b5d32cf893d88ac09cfefa8ef3afeb3c0e7b726a71272a07350109657effb1dfdc205db49cf02d23d10880d8468206f95b4cd7b146695f
 DIST openmw-template-8966dab24692555eec720c854fb0f73d108070cd.omwgame 139730 BLAKE2B bf7f96912fd828078c62d112f3ff83e9a35298516135fb46b15ed01fc0260247cc0cba4aa3bbc55bf6a688f216384dbd9a5aa3328c4387b9b180b80f7463963e SHA512 6e38642bcf013c5f496a9cb0bf3ec7c9553b6e86b836e7844824c5a05f556c9391167214469b6318401684b702d7569896bf743c85aee4198612b3315ba778d6
diff --git a/games-engines/openmw/files/openmw-0.51.0-gcc17.patch b/games-engines/openmw/files/openmw-0.51.0-gcc17.patch
new file mode 100644
index 0000000000000..4c52a9e28137a
--- /dev/null
+++ b/games-engines/openmw/files/openmw-0.51.0-gcc17.patch
@@ -0,0 +1,15 @@
+Fix build with GCC 17
+
+https://bugs.gentoo.org/976979
+https://gitlab.com/OpenMW/openmw/-/merge_requests/5346
+
+--- a/apps/wizard/unshield/inisettings.hpp
++++ b/apps/wizard/unshield/inisettings.hpp
+@@ -1,6 +1,7 @@
+ #ifndef INISETTINGS_HPP
+ #define INISETTINGS_HPP
+ 
++#include <fstream>
+ #include <QHash>
+ #include <QVariant>
+ 
diff --git a/games-engines/openmw/openmw-0.51.0.ebuild b/games-engines/openmw/openmw-0.51.0.ebuild
new file mode 100644
index 0000000000000..f7cc51dfba37f
--- /dev/null
+++ b/games-engines/openmw/openmw-0.51.0.ebuild
@@ -0,0 +1,191 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+LUA_COMPAT=( lua5-{1,3,4} luajit )
+inherit cmake lua-single readme.gentoo-r1 xdg
+
+DESCRIPTION="Open source reimplementation of TES III: Morrowind"
+HOMEPAGE="https://openmw.org/ https://gitlab.com/OpenMW/openmw"
+
+if [[ ${PV} == *9999* ]]; then
+	inherit git-r3
+	EGIT_REPO_URI="https://github.com/OpenMW/openmw.git"
+else
+	SRC_URI="https://github.com/OpenMW/openmw/archive/${P}.tar.gz"
+	S="${WORKDIR}/${PN}-${P}"
+	KEYWORDS="~amd64 ~arm64 ~ppc64"
+fi
+
+# This particular commit is hardcoded in
+# https://gitlab.com/OpenMW/openmw/-/blob/ffe164b28d3a10408e20fdadd2f0168c1e32fd6e/apps/components_tests/CMakeLists.txt#L114-118
+MY_TEMPLATE_COMMIT="8966dab24692555eec720c854fb0f73d108070cd"
+SRC_URI+="
+	test? (
+		https://gitlab.com/OpenMW/example-suite/-/raw/${MY_TEMPLATE_COMMIT}/game_template/data/template.omwgame
+		-> openmw-template-${MY_TEMPLATE_COMMIT}.omwgame
+	)
+"
+
+LICENSE="GPL-3 MIT BitstreamVera ZLIB"
+SLOT="0"
+IUSE="doc devtools +gui +osg-fork test"
+REQUIRED_USE="${LUA_REQUIRED_USE}"
+RESTRICT="!test? ( test )"
+
+# TODO: Unbundle dev-games/openscenegraph-qt in extern/osgQt directory,
+# used when BUILD_OPENCS flag is enabled.
+# OpenMW has custom changes to this library.
+# See bug #676266.
+
+RDEPEND="${LUA_DEPS}
+	app-arch/lz4:=
+	dev-cpp/yaml-cpp:=
+	dev-db/sqlite:3
+	dev-games/recastnavigation:=
+	dev-libs/collada-dom:=
+	>=dev-games/mygui-3.4.3:=
+	dev-libs/boost:=[zlib]
+	dev-libs/icu:=
+	dev-libs/tinyxml[stl]
+	media-libs/libsdl2[joystick,opengl,video]
+	media-libs/openal
+	media-video/ffmpeg:=
+	>=sci-physics/bullet-2.86:=[double-precision]
+	virtual/zlib:=
+	virtual/opengl
+	osg-fork? ( >=dev-games/openscenegraph-openmw-3.6:=[collada(-),jpeg,png,sdl,svg,truetype,zlib] )
+	!osg-fork? ( >=dev-games/openscenegraph-3.6.5:=[collada(-),jpeg,png,sdl,svg,truetype,zlib] )
+	gui? (
+		app-arch/unshield:=
+		dev-qt/qtbase:6[gui,network,opengl,widgets]
+		dev-qt/qtsvg:6
+	)
+"
+
+BDEPEND="
+	virtual/pkgconfig
+	doc? (
+		app-text/doxygen[dot]
+		dev-python/sphinx
+	)
+	gui? (
+		dev-qt/qttools:6[linguist]
+	)
+	test? (
+		dev-cpp/gtest
+	)
+"
+
+PATCHES=(
+	"${FILESDIR}/openmw-0.51.0-gcc17.patch"
+)
+
+src_configure() {
+	use devtools && ! use gui &&
+		elog "'gui' USE flag is disabled, 'openmw-cs' will not be installed"
+
+	local mycmakeargs=(
+		-DBUILD_BSATOOL=$(usex devtools)
+		-DBUILD_DOCS=$(usex doc)
+		-DBUILD_ESMTOOL=$(usex devtools)
+		-DBUILD_LAUNCHER=$(usex gui)
+		-DBUILD_OPENCS=$(usex devtools $(usex gui))
+		-DBUILD_WIZARD=$(usex gui)
+		-DBUILD_NIFTEST=$(usex devtools)
+		-DBUILD_COMPONENTS_TESTS=$(usex test)
+		-DBUILD_OPENMW_TESTS=$(usex test)
+		-DBUILD_OPENCS_TESTS=$(usex test $(usex devtools))
+
+		-DGLOBAL_DATA_PATH="${EPREFIX}/usr/share"
+		-DICONDIR="${EPREFIX}/usr/share/icons/hicolor/256x256/apps"
+		-DUSE_SYSTEM_TINYXML=ON
+		-DOPENMW_USE_SYSTEM_GOOGLETEST=ON
+		-DOPENMW_USE_SYSTEM_RECASTNAVIGATION=ON
+		-DOPENMW_USE_SYSTEM_SQLITE3=ON
+
+		-DQT_DIR="${ESYSROOT}/usr/lib64/cmake/Qt6"
+	)
+
+	if [[ ${ELUA} == luajit ]]; then
+		mycmakeargs+=(
+			-DUSE_LUAJIT=ON
+		)
+	else
+		mycmakeargs+=(
+			-DUSE_LUAJIT=OFF
+			-DLua_FIND_VERSION_MAJOR=$(ver_cut 1 $(lua_get_version))
+			-DLua_FIND_VERSION_MINOR=$(ver_cut 2 $(lua_get_version))
+			-DLua_FIND_VERSION_COUNT=2
+			-DLua_FIND_VERSION_EXACT=ON
+		)
+	fi
+
+	if use test ; then
+		mkdir -p "${BUILD_DIR}"/apps/components_tests/data || die
+		cp "${DISTDIR}"/openmw-template-${MY_TEMPLATE_COMMIT}.omwgame \
+			"${BUILD_DIR}"/apps/components_tests/data/template.omwgame || die
+	fi
+
+	cmake_src_configure
+}
+
+src_compile() {
+	cmake_src_compile
+
+	if use doc ; then
+		cmake_src_compile doc
+		find "${BUILD_DIR}"/docs/Doxygen/html \
+			-name '*.md5' -type f -delete || die
+		HTML_DOCS=( "${BUILD_DIR}"/docs/Doxygen/html/. )
+	fi
+}
+
+src_test() {
+	# Lua 5.x is supported in theory, but don't work as well, the test fails
+	# Upstream recommends luajit, but it has less arch coverage
+	if [[ ${ELUA} != luajit ]]; then
+		elog "Skipping tests on ${ELUA}"
+		return
+	fi
+
+	pushd "${BUILD_DIR}" > /dev/null || die
+	./components-tests || die
+	./openmw-tests || die
+	if use gui && use devtools; then
+		./openmw-cs-tests || die
+	fi
+	popd > /dev/null || die
+}
+
+src_install() {
+	cmake_src_install
+
+	local DOC_CONTENTS="
+	You need the original Morrowind data files. If you haven't
+	installed them yet, you can install them straight via the
+	installation wizard which is the officially supported method
+	(either by using the launcher or by calling 'openmw-wizard'
+	directly).\n"
+
+	if ! use gui ; then
+		DOC_CONTENTS+="\n\n
+		USE flag 'gui' is disabled, 'openmw-launcher' and
+		'openmw-wizard' are not available. You are on your own for
+		making the Morrowind data files available and pointing
+		openmw at them.\n\n
+		Additionally; you must import the Morrowind.ini file before
+		running openmw with the Morrowind data files for the first
+		time. Typically this can be done like so:\n\n
+		\t mkdir -p ~/.config/openmw\n
+		\t openmw-iniimporter /path/to/Morrowind.ini ~/.config/openmw/openmw.cfg"
+	fi
+
+	readme.gentoo_create_doc
+}
+
+pkg_postinst() {
+	xdg_pkg_postinst
+	readme.gentoo_print_elog
+}