Gilliam is an English surname. Notable people with the surname include:
Armen Gilliam (1964–2011), American basketball player Burton Gilliam (born 1938), American actor Colt Gilliam (born 1989), American racing driver Cornelius Gilliam (1798–1848), American pioneer, politician, and army commander Frank Gilliam (disambiguation), multiple people Garry Gilliam (born 1990), American football player Herm Gilliam (1946–2005), American basketball player Jackson Earle Gilliam (1920–2000), American bishop James Frank Gilliam (1915–1990), American historian Jim Gilliam (1928–1978), American baseball player John Gilliam (born 1945), American football player Joe Gilliam (1950–2000), American football player Holly Michelle Gilliam (born 1944), birth name of American singer and actress Michelle Phillips Makayla Gilliam-Price, American social activist Reggie Gilliam (born 1997), American football player Robert B. Gilliam (1805–1870), American politician and judge Sam Gilliam (1933–2022), American artist Seth Gilliam (born 1968), American actor Stu Gilliam (1933–2013), American actor and comedian Terry Gilliam (born 1940), American-born British film director Tyrone Delano Gilliam Jr. (1966–1998), American murderer William Gilliam (1841–1893), American politician