Byrnes is a surname. Notable people with the surname include:
Edd Byrnes, American actorEsther Byrnes (1867–1946), American biologist and science teacherGarrett Byrnes, American composerGene Byrnes, American comic artistJames F. Byrnes, US politician and U.S. Secretary of StateJohn W. Byrnes, US politicianJo Byrns, US politicianJosh Byrnes, manager of the Arizona DiamondbacksEric Byrnes, American baseball playerKevin P. Byrnes, U.S. Army 4-star generalNorman Byrnes (botanist), AustralianNorman Byrnes (lawyer), AmericanPat Byrnes, American cartoonistShannon Byrnes, Australian rules playerSteve Byrnes, television announcer and producerThomas F. Byrnes, 19th Century New York City police inspectorThomas Joseph Byrnes, premier of Queensland