Jack Montrose (December 30, 1928 – February 7, 2006) was an American jazz tenor saxophonist and arranger. After attending college in Los Angeles, he worked with Jerry Gray and then Art Pepper. Montrose also did arrangements for Clifford Brown. He became known for cool jazz and/or West coast jazz.

Montrose was born in Detroit. Beginning in the mid-1950s Montrose's heroin addiction became a liability and by the time he had overcome it his style of jazz was no longer popular. This led him to play in strip joints for a time until he relocated to Las Vegas where he worked in casinos. Montrose returned to recording in 1977 and in 1986 had some success in collaboration with Pete Jolly.

Jack Montrose (West Coast Jack) is not to be confused with tenorist J.R. Monterose (East Coast Jake) who played on Charles Mingus's album Pithecanthropus Erectus.

He died in Las Vegas.