John Grimes

• John Grimes (bishop of Christchurch), first Roman Catholic bishop of Christchurch, New Zealand
• John Grimes (bishop of Syracuse), Roman Catholic bishop
• John Bryan Grimes, North Carolina Democratic politician and farmer
• John Grimes (baseball), American baseball player
• John Grimes (priest), Anglican Archdeacon of Northampton
• John Grimes, former U.S. Assistant Secretary of Defense for Networks and Information Integration
• John Grimes (singer), member of the Irish pop rap duo Jedward
• John Grimes, fictional character in a series of novels by A. Bertram Chandler
• John Grimes, fictional character in the film Black Hawk Down
• Dr. John Grimes, Quaker anti-slavery advocate and namesake of the Grimes Homestead