James P. Collman (born 1932) is an American chemist who is the George A. and Hilda M. Daubert Professor of Chemistry, emeritus at Stanford University.
After serving as an Instructor at the University of North Carolina at Chapel Hill for one year, he was hired as an assistant professor in 1959.
In the 1960s his group demonstrated that certain metal acetylacetonates undergo Friedel-Crafts-like reactions, indicating that these chelate rings have aromatic character.
In the area of organometallic chemistry, through reviews as well as original research, his group popularized the oxidative addition reaction, leading to the discovery of new low-valent complexes including Ru(CO)3(PPh3)2 and IrCl(N2)(PPh3)2.
Two of his postdoctoral researchers at Stanford, Karl Barry Sharpless and Robert H. Grubbs, later received Nobel Prizes in Chemistry.