Vinyldiphenylphosphine is the organophosphorus compound with the formula (C<sub>6</sub>H<sub>5</sub>)<sub>2</sub>PCH=CH<sub>2</sub>. This colorless, air-sensitive solid is used as a precursor to ligands used in coordination chemistry and homogeneous catalysis. It is prepared by treating chlorodiphenylphosphine with vinyl Grignard reagents.