diff --git a/www-client/opera-developer/Manifest b/www-client/opera-developer/Manifest
index 473233f45eb14..11d8d3bb5494e 100644
--- a/www-client/opera-developer/Manifest
+++ b/www-client/opera-developer/Manifest
@@ -1,3 +1,4 @@
 DIST opera-developer_120.0.5530.0_amd64.deb 128353556 BLAKE2B 44bc5d6f3d4acd870dd7bec01152d37f2f4172fb7c3866febcc5fb4a89d856840bc3265bbc163b915acdabd04fd7d642ca3b23a35b40796f1ca88f4472604fd3 SHA512 32cb460c6ac8faa4b5b7af13d9efb89f61a521dcef4eb3aba5d99f7524a18e271625c59d0681d2317e38707c46e34da8d6b9cf0e96dd9aeda04c27fdc911b1f8
 DIST opera-developer_121.0.5544.0_amd64.deb 131630476 BLAKE2B c44e36fa709437bf37f5c50ebd87cfb49be0e847def0c8eeae59f2a6a0832698a691712fb5b3b6230413107e8d9808cda89eda9d10317bc05dbee00e96d20c14 SHA512 ab71f23325e6a827d1e239f292e79c59052888720d6fdb33a93717f90a671276ce6bb7ac38431e944c128ffa2d9fdd1b98d619b48a2baf9852547f59a94c3968
 DIST opera-developer_121.0.5551.0_amd64.deb 131997812 BLAKE2B 053eee744787c9ad5bd50f0bb20365df573c6036cbbd6bd23eaadffad3a00f82797d2db5e363bf9934d5e5a96a0f811c810b4df9f72895e7d5cd7b0ea123bcf1 SHA512 6f02644ec869f6b4260f307da6ae08a02a6bf95086d803f913158bd2f6cf14b40f6dd7bd5bec7ff3984bf2608ab68f6edffb71414e6bfe658189ce8c7dfc3570
+DIST opera-developer_121.0.5558.0_amd64.deb 132133580 BLAKE2B 2d6fd7ccdc6cfb9587ec8c70317b19e37463a1e5344c2c7be12c8035220e29b4adbe4feb81b32eacb9189230be711063392c485badda63960907a20004b2d31e SHA512 c607b03db11c3bec17789e073f25a6938e00b64841ae85e4aa957fd0a5b6479e4fe5d97f5d17b8b1eadd81c085961dbed69c218534e10977ddab5bf16c8cca01
diff --git a/www-client/opera-developer/opera-developer-121.0.5558.0.ebuild b/www-client/opera-developer/opera-developer-121.0.5558.0.ebuild
new file mode 100644
index 0000000000000..f176df4d5a72f
--- /dev/null
+++ b/www-client/opera-developer/opera-developer-121.0.5558.0.ebuild
@@ -0,0 +1,166 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+CHROMIUM_LANGS="
+	bg bn ca cs da de el en-GB en-US es-419 es fil fi fr hi hr hu id
+	it ja ko lt lv ms nb nl pl pt-BR pt-PT ro ru sk sr sv sw ta te th tr uk vi
+	zh-CN zh-TW
+"
+
+# These are intended for ebuild maintainer use to force RPM if DEB is not available.
+: ${OPERA_FORCE_RPM=no}
+
+inherit chromium-2 pax-utils xdg
+
+if [[ ${OPERA_FORCE_RPM} == yes ]]; then
+	inherit rpm
+	OPERA_ARCHIVE_EXT="rpm"
+else
+	inherit unpacker
+	OPERA_ARCHIVE_EXT="deb"
+fi
+
+DESCRIPTION="A fast and secure web browser"
+HOMEPAGE="https://www.opera.com/"
+
+SRC_URI_BASE=(
+	"https://download1.operacdn.com/pub/${PN}"
+	"https://download2.operacdn.com/pub/${PN}"
+	"https://download3.operacdn.com/pub/${PN}"
+	"https://download4.operacdn.com/pub/${PN}"
+)
+
+if [[ ${PN} == opera ]]; then
+	MY_PN=${PN}-stable
+	SRC_URI_BASE=( "${SRC_URI_BASE[@]/%//desktop}" )
+else
+	MY_PN=${PN}
+fi
+
+# Commit ref from `strings libffmpeg.so | grep -F "FFmpeg version"` matches this Chromium version
+# used to select the correct ffmpeg-chromium version (corresponds to a major version of Chromium)
+# Does not need to be updated for every new version of Opera, only when it breaks
+CHROMIUM_VERSION="134"
+SRC_URI="${SRC_URI_BASE[@]/%//${PV}/linux/${MY_PN}_${PV}_amd64.${OPERA_ARCHIVE_EXT}}"
+S=${WORKDIR}
+
+LICENSE="OPERA-2018"
+SLOT="0"
+KEYWORDS="-* ~amd64"
+IUSE="+ffmpeg-chromium +proprietary-codecs +suid qt6"
+RESTRICT="bindist mirror strip"
+
+RDEPEND="
+	>=app-accessibility/at-spi2-core-2.46.0:2
+	dev-libs/expat
+	dev-libs/glib:2
+	dev-libs/nspr
+	dev-libs/nss
+	gnome-base/gsettings-desktop-schemas
+	media-libs/alsa-lib
+	media-libs/mesa[gbm(+)]
+	net-misc/curl
+	net-print/cups
+	sys-apps/dbus
+	sys-libs/glibc
+	x11-libs/cairo
+	x11-libs/gdk-pixbuf
+	x11-libs/gtk+:3
+	x11-libs/libdrm
+	x11-libs/libxcb
+	x11-libs/libxkbcommon
+	x11-libs/libxshmfence
+	x11-libs/libX11
+	x11-libs/libXcomposite
+	x11-libs/libXdamage
+	x11-libs/libXext
+	x11-libs/libXfixes
+	x11-libs/libXrandr
+	x11-libs/pango
+	proprietary-codecs? (
+		!ffmpeg-chromium? ( >=media-video/ffmpeg-6.1-r1:0/58.60.60[chromium] )
+		ffmpeg-chromium? ( media-video/ffmpeg-chromium:${CHROMIUM_VERSION} )
+	)
+	qt6? ( dev-qt/qtbase:6[gui,widgets] )
+"
+
+QA_PREBUILT="*"
+OPERA_HOME="opt/opera${PN#opera}"
+
+pkg_pretend() {
+	# Protect against people using autounmask overzealously
+	use amd64 || die "opera only works on amd64"
+}
+
+pkg_setup() {
+	chromium_suid_sandbox_check_kernel_config
+}
+
+src_unpack() {
+	:
+}
+
+src_install() {
+	dodir /
+	cd "${ED}" || die
+	if [[ ${OPERA_FORCE_RPM} == yes ]]; then
+		rpm_src_unpack "${A[0]}"
+	else
+		unpacker
+	fi
+
+	# move to /opt, bug #573052
+	mkdir -p "${OPERA_HOME%${PN}}"
+	if [[ ${OPERA_FORCE_RPM} == yes ]]; then
+		mv "usr/lib64/${PN}" "${OPERA_HOME%${PN}}" || die
+	else
+		mv "usr/lib/x86_64-linux-gnu/${PN}" "${OPERA_HOME%${PN}}" || die
+	fi
+	rm -r "usr/lib" || die
+
+	# disable auto update
+	rm "${OPERA_HOME}/${PN%-*}_autoupdate"{,.licenses,.version} || die
+
+	if [[ ${OPERA_FORCE_RPM} == yes ]]; then
+		rm "${OPERA_HOME}/setup_repo.sh" || die
+	else
+		rm -r "usr/share/lintian" || die
+
+		# fix docs
+		mv usr/share/doc/${MY_PN} usr/share/doc/${PF} || die
+		gzip -d usr/share/doc/${PF}/changelog.gz || die
+	fi
+
+	# fix desktop file
+	sed -i \
+		-e 's|^TargetEnvironment|X-&|g' \
+		usr/share/applications/${PN}.desktop || die
+
+	# remove unused language packs
+	pushd "${OPERA_HOME}/localization" > /dev/null || die
+	chromium_remove_language_paks
+	popd > /dev/null || die
+
+	# setup opera symlink
+	rm "usr/bin/${PN}" || die
+	dosym "../../${OPERA_HOME}/${PN}" "/usr/bin/${PN}"
+
+	# install proprietary codecs
+	rm "${OPERA_HOME}/resources/ffmpeg_preload_config.json" || die
+	if use proprietary-codecs; then
+		dosym ../../usr/$(get_libdir)/chromium/libffmpeg.so$(usex ffmpeg-chromium .${CHROMIUM_VERSION} "") \
+			  /${OPERA_HOME}/libffmpeg.so
+	fi
+
+	rm "${OPERA_HOME}/libqt5_shim.so" || die
+	if ! use qt6; then
+		rm "${OPERA_HOME}/libqt6_shim.so" || die
+	fi
+
+	# pax mark opera, bug #562038
+	pax-mark m "${OPERA_HOME}/opera"
+	# enable suid sandbox if requested
+	use suid && fperms 4711 "/${OPERA_HOME}/opera_sandbox"
+}