Robert Howard Grubbs (born on 27 February 1942 in Possum Trot, Kentucky, U.S.A.) is an American chemist and the Nobel Prize Laureate for Chemistry in 2005 (along with Richard R. Schrock and Yves Chauvin) for his work in the field of olefin metathesis.

He spent his early childhood in Kentucky and attended public school at McKinley Elementary, Franklin Junior High and Paducah Tilghman High School. Grubbs received higher education in Florida and Columbia Universities. In 1968 he received his PhD and in 1969 he started working at Stanford, then at the University of Michigan. In 1978 he became a member of the California Institute of Technology, where he works today.

His main interests in organometallic chemistry and synthetic chemistry are catalysts, notably Grubbs' catalyst for olefin metathesis. He also contributed to the development of so-called "living polymerization". In 1989 Grubbs was elected to the National Academy of Sciences of the USA, and in 1994 became a member of the American Academy of Arts and Sciences.

Grubbs is married to Helen Grubbs, a retired SLP elementary school teacher, with whom he has three children—all of whom have earned a PhD or an M.D.

"Drug addiction is awful and terrible. I'm not interested in drugs and do not recommend it to anyone."