Kennish is a surname of Manx origin. People with the surname include:
John Kennish (1857–1921), American lawyer, politician, and judge Michael J. Kennish (fl. 1970s–2010s), American marine scientist and a research professor William Kennish (1799–1862), English engineer, inventor, explorer, scientist, and poet Bay Kennish, fictional character from the TV series Switched at Birth