Gregory or Greg Martin may refer to:

• Gregory Martin (scholar) (c. 1542–1582), Catholic Priest, scholar, and Bible translator
• Gregory Martin (wrestler), professional wrestler, see MCW Cruiserweight Championship
• Greg Martin (entrepreneur), entrepreneur and cyber security expert
• Sir Greg Martin, London, executive headteacher
• Gregory J. Martin, American medical doctor and U.S. Navy captain
• Gregory Paul Martin (born 1957), British actor
• Gregory S. Martin (born 1948), USAF general
• Greg Martin (rugby union) (born 1963), Australian rugby union player
• Greg Martin (politician) (born 1963), American politician in the Tennessee House of Representatives
• Greg Martin, American actor and assistant director featured in The Great Waldo Pepper and Berks
• Greg Martin, member of The Kentucky Headhunters
• Greg Martin, Filipino 50's actor.
• Greg Martin, Filipino 2000s actor and model.