Billy McMillan (died 1991) was an Irish footballer.
Billy McMillan may also refer to: Billy MacMillan (1943–2023), Canadian hockey player and coach Billy McMillen (1927–1975), Irish republican activist and an officer of the Official Irish Republican Army Billy McMillon (born 1971), American baseball player
See also Bill MacMillan (academic) (born 1950), British academic and former vice-chancellor William MacMillan (disambiguation)