Robert David Grusin (born June 26, 1934) is an American composer, arranger, producer, and pianist. He has composed many scores for feature films and television, and has won numerous awards for his soundtrack and record work, including an Academy Award and ten Grammy Awards. He is the co-founder of GRP Records.

Grusin was born in Littleton, Colorado, to Henri and Rosabelle (née de Poyster) Grusin. His mother was a pianist and his father was a violinist from Riga, Latvia. He has one Jewish parent.

He studied music at the University of Colorado at Boulder and was awarded his degree in 1956. His teachers included Cecil Effinger and Wayne Scott, pianist, arranger and professor of jazz.