diff --git a/dev-lang/swig/Manifest b/dev-lang/swig/Manifest
index 49b8925910f76..2f152fc3060b8 100644
--- a/dev-lang/swig/Manifest
+++ b/dev-lang/swig/Manifest
@@ -2,3 +2,4 @@ DIST swig-4.1.1.tar.gz 8600805 BLAKE2B 898d3405f20c3e49626fb808b568e77c69b81ec24
 DIST swig-4.2.1.tar.gz 8364050 BLAKE2B 0acffd4794d09f2347d669d1460a794c03f136ab3ddc6623741e182ff52b6bf5f639c736e38540918ebb1abbe36c2ce1957aef8a429f1a716d9c5361175569bf SHA512 019dee5a46d57e1030eef47cd5d007ccaadbdcd4e53cd30d7c795f0118ecf4406a78185534502c81c5f6d7bac0713256e7e19b20b5a2d14e2c552219edbaf5cf
 DIST swig-4.3.1.tar.gz 8620774 BLAKE2B cd47eb3f9bf7c7e2f1583a58c4416275720b55754abd05c61636e68ac36e6b5899b293e55cf680071257017b53b95e7a2fd8983ca4effc7e98bb7af4dac5e026 SHA512 8958f7bc3345549a9bc4e00aa8d40a99f6c4bb92b95d627c8796cf8f8d1ba0041a89cab542f171778c2b26aa2a877767181ae9bd2c05fd055f373a32a463399c
 DIST swig-4.4.1.tar.gz 8658358 BLAKE2B 06fdcda2de0b0acf341949e0d60e284b5cd326a1f0f1d0985e387c936ef8d87fb98ea14a260ca22c19634f297f7331ed44989da07a47ee9333630397846e4db1 SHA512 103ddb4a5914f28e6739a006d35042c701e55ba05066acff3f3609befb5f43f253ea717fc41d06c93d8fb187ded4399c12c94665b93dc06d0fb835069391c7c7
+DIST swig-4.5.1.tar.gz 9191718 BLAKE2B 371086611526fc7ac437d09c6f12c4077c31b4d3b7d89facfc67363114a42202c5a715e61822b64015c1fa2e1f8c3222566dfe1482ba927a71fbfc2c4439643b SHA512 bf89652ddcfac38e42a52224ff79c5717e973779d174b822a03ad48866303779cadf9d5181bbceed4d5dd4a0ff5ed5dea4a0c7cf10c5bc4a59310cdba64f47dd
diff --git a/dev-lang/swig/metadata.xml b/dev-lang/swig/metadata.xml
index 9643318f6cf34..7490c7d8f9120 100644
--- a/dev-lang/swig/metadata.xml
+++ b/dev-lang/swig/metadata.xml
@@ -16,6 +16,7 @@
 	</longdescription>
 	<use>
 		<flag name="ccache">build ccache-swig(a fast compiler cache)</flag>
+		<flag name="test-full">Test against more languages</flag>
 	</use>
 	<upstream>
 		<remote-id type="github">swig/swig</remote-id>
diff --git a/dev-lang/swig/swig-4.5.1.ebuild b/dev-lang/swig/swig-4.5.1.ebuild
new file mode 100644
index 0000000000000..a48b9ffc39fe3
--- /dev/null
+++ b/dev-lang/swig/swig-4.5.1.ebuild
@@ -0,0 +1,117 @@
+# Copyright 1999-2026 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{12..15} )
+inherit flag-o-matic python-any-r1 toolchain-funcs
+
+DESCRIPTION="Simplified Wrapper and Interface Generator"
+HOMEPAGE="https://www.swig.org/ https://github.com/swig/swig"
+SRC_URI="https://downloads.sourceforge.net/project/swig/swig/${P}/${P}.tar.gz"
+
+LICENSE="GPL-3+ BSD BSD-2"
+SLOT="0"
+# Temporarily unkeyworded due to breakage in reverse dependencies, bug #983043
+#KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~arm64-macos ~x64-macos ~x64-solaris"
+IUSE="ccache doc pcre test test-full"
+RESTRICT="!test? ( test )"
+
+RDEPEND="
+	pcre? ( dev-libs/libpcre2:= )
+	ccache? ( virtual/zlib:= )
+"
+DEPEND="
+	${RDEPEND}
+	test? ( dev-libs/boost )
+"
+BDEPEND="
+	virtual/pkgconfig
+	test? (
+		${PYTHON_DEPS}
+		test-full? (
+			dev-lang/mono
+			>=dev-lang/go-1.20
+			virtual/jdk
+			>=dev-lang/lua-5.1:*
+			dev-lang/ocaml
+			dev-lang/perl:*
+			|| (
+				dev-lang/php:8.3
+				dev-lang/php:8.2
+			)
+			dev-lang/R
+			dev-lang/tcl
+		)
+	)
+"
+
+DOCS=( ANNOUNCE CHANGES CHANGES.current README TODO )
+
+pkg_setup() {
+	use test && python-any-r1_pkg_setup
+}
+
+src_configure() {
+	# strict aliasing violations in test code
+	filter-lto
+	append-flags -fno-strict-aliasing
+
+	local myconf=(
+		PKGCONFIG="$(tc-getPKG_CONFIG)"
+		--without-maximum-compile-warnings
+		$(use_enable ccache)
+		$(use_with pcre)
+		--without-clang-format
+
+		# tests are automagic for many languages otherwise and may be quite brittle
+		--without-alllang
+		--with-python # installed by default due to portage, significant portion of revdeps use swig for python bindings
+	)
+	if use test-full; then
+		myconf+=(
+			--with-csharp
+			#--with-d # doesn't accept gcc[d]?
+			--with-go
+			#--with-guile would need guile-any type support
+			--with-java
+			#--with-javascript # broken build
+			--with-lua
+			--with-ocaml
+			#--with-octave # broken build
+			--with-perl
+			--with-perl5="${EPREFIX}/usr/bin/perl"
+			--with-php
+			--with-r
+			#--with-ruby # broken build
+			#--with-scilab # not packaged?
+			--with-tcl
+		)
+	fi
+	econf "${myconf[@]}"
+}
+
+src_compile() {
+	# Override these variables per Makefile.in to get verbose logs
+	emake FLAGS="-k" RUNPIPE=""
+}
+
+src_test() {
+	# The tests won't get run w/o an explicit call, broken Makefiles?
+	# *-sections for bug #935318
+	emake check \
+		FLAGS="-k" \
+		RUNPIPE="" \
+		CFLAGS="${CFLAGS} -ffunction-sections -fdata-sections" \
+		CXXFLAGS="${CXXFLAGS} -ffunction-sections -fdata-sections" \
+		LDFLAGS="${LDFLAGS}"
+}
+
+src_install() {
+	default
+
+	if use doc; then
+		docinto html
+		dodoc -r Doc/{Devel,Manual}
+	fi
+}