Jack Barnes

• Jack Barnes (politician), American communist and the National Secretary of the Socialist Workers Party
• Jack Barnes (English footballer), English association footballer
• Jack Barnes (Australian footballer), Australian rules footballer
• Jack Barnes (rugby league), English rugby league player
• Jack Barnes (toxinologist), Australian toxinologist
• Jack Barnes (high jumper), American high jumper, 1949 All-American for the USC [Trojans track and field] team