Grant Geissman (born April 13, 1953) is a crossover jazz, contemporary jazz and new-age guitarist and an Emmy-nominated composer for network TV series and TV movies. An in-demand studio musician, he has recorded extensively for several labels since 1976, and he can be heard playing guitar on the theme for Monk and other TV series.

Geissman was born in Berkeley, California. Growing up in San Jose, California, Geissman took guitar lessons from a succession of San Jose musicians, including Geoff Levin (of the pop group People!) and local jazz favorites Bud Dimock, Don Cirallo and Terry Saunders. Encouraged by these teachers to learn jazz standards and to improvise, he began playing in rock bands on weekends and also with small jazz groups and big bands.