Bimetallic　clusters　anchored　on　thermally　stable　and　high-surface-area　supports　have　gained　a　wide　range　of　applications　in　heterogeneous　catalysis.　Compared　to　monometallic　clusters　or　large　bimetallic　nanoparticles,　bimetallic　clusters　show　unprecedented　catalytic　performances　due　to　the　modulated　electronic　and　geometric　effects　arising　from　the　high　fraction　of　surface　unsaturated-coordinated　metallic　atoms　and　the　synergistic　effects　between　two　constituting　metals.　However,　even　after　more　than　60　years　of　efforts,　the　controlled　synthesis　of　homogeneously　distributed　bimetallic　clusters　with　well-alloyed　structure　between　two　constituting　metals　remains　a　tremendous　challenge　so　far.　Herein,　we　present　a　versatile　strategy　based　on　the　surface　organometallic　chemistry　concept　for　synthesizing　supported　bimetallic　cluster　catalysts,　which　is　achieved　via　the　hydrogenation　of　a　so-called　＂double　surface　organometallic　complex＂.　The　cooperative　decomposition　of　two　surface　organometallic　fragments　in　the　double　surface　organometallic　complex　and　their　strong　interaction　with　the　support　enable　the　formation　of　well-alloyed　bimetallic　clusters　uniformly　dispersed　at　the　surfaces　of　different　supports.　This　approach　can　serve　as　a　platform　technique　for　producing　a　variety　of　bimetallic　clusters　with　varied　compositions　on　a　wide　range　of　supports,　such　as　Al2O3,　TiO2,　and　zeolite.　The　resulting　bimetallic　cluster　catalysts　exhibit　remarkably　enhanced　catalytic　performance　in　benzene　hydrogenation　as　compared　to　their　monometallic　counterparts　because　of　highly　exposed　surface　atoms　and　synergistic　effects　between　constituting　metals.　©　2022　American　Chemical　Society.