Killilea is a surname originating in Ireland. Notable people with the surname include:
Henry Killilea (1863–1929), American baseball team owner and attorney Karen Killilea (1940-2020), Marie Killilea's daughter with cerebral palsy Marie Killilea (1913–91), American author and cerebral palsy activist Mark Killilea Snr (1896–1970), Irish politician Mark Killilea Jnr (1939-2018), Irish politician Matthew Killilea (1862–1902), American lawyer and politician