Killen is a surname. Notable people with the surname include:
Bill Killen (born 1938), American politician Chris Killen (born 1981), New Zealand football player Edgar Ray Killen (1925–2018), American criminal Eric Lyle Killen (1892–1955), Australian pastoralist Frank Killen (1870–1939), American baseball player Ged Killen, British politician James Killen (1925–2007), Australian politician Lou Killen (1934–2013), English folk singer M. Evelyn Killen (1871-1951), American temperance advocate William Dool Killen (1806–1902), Irish Presbyterian minister and church historian William Wilson Killen (1860–1939), Australian politician
See also Killens