[Ru(PyO)2(nbd)] (1) (PyO = 2‐pyridyloxy, nbd = norbornadiene) and PhP(PyO)2 react with formation of complex [PhP(µ‐PyO)3Ru(κ‐PyO)] (2), which features a Ru–P bond between a pentacoordinate P atom and a hexacoordinate Ru atom, bridged by three PyO ligands. Addition of CO leads to opening of the Ru(κ‐PyO) chelate with formation of complex [PhP(µ‐PyO)4Ru(CO)] (3), a paddlewheel‐shaped complex with a Ru–P bond between a hexacoordinate P atom and a hexacoordinate Ru atom, bridged by four PyO ligands. In complexes 2 and 3 the P atom serves as a lone pair donor toward Ru. Interestingly, the P atom also serves as a ligand acceptor, thus enhancing its coordination number and generating a coordination site at Ru. These complexes were studied by multinuclear NMR spectroscopy, cyclic voltammetry, and quantum chemical calculations (NBO/NLMO analyses).