O'Hearn is an English/Irish surname. As an English surname, it can derive firstly from an early medieval nickname for someone thought to resemble the Heron bird. Notable people with the surname include:
Ed O'Hearn (1898–unknown), American professional football playerGeorge E. O'Hearn, American college football coachJohn O'Hearn (1893–1977), American professional football playerMelinda O'Hearn (alias Midajah; born 1973), American actress, singer and fitness modelMichael O'Hearn (born 1969), American bodybuilderPatrick O'Hearn (born 1954), American multi-instrumentalist musician, composer and recording artistPeter O'Hearn (born 1963), British-Canadian computer scientistTaylor W. O'Hearn (1907–1997), American politician from LouisianaWalter O'Hearn (1890–1950), Australian politicianWalter D. O'Hearn (1910–1970?), prominent Canadian journalist in the mid-20th centuryZooko Wilcox-O'Hearn (born Bryce Wilcox-O'Hearn), American computer hacker and cypherpunkDaniel O'Hearn, Canadian bartender, mixologist and renowned real estate agent located in the Vancouver area.