McMillen or MacMillen is a surname. The origin of the name derives from the origin of the Scottish Clan MacMillan; see also the similar surname McMillan. Notable people with the surname include:

Andrew McMillen (born c. 1988), Australian journalist Andrew Robinson McMillen, Canadian politician Billy McMillen (1920–1975), Irish republican Bob McMillen (1928–2007), American athlete Bob McMillen (born 1970), American football player and coach Clara McMillen (1898–1982), American biologist Dale W. McMillen (1880–1971), American businessman Edmund McMillen (born 1980), American video game designer Jim McMillen (1902–1984), American football player Loring McMillen (1906–1991), American engineer and historian Louis A. McMillen (1916–1998), American architect Neil R. McMillen, American historian Rolla C. McMillen (1880–1961), American politician Thomas Roberts McMillen (1916–2002), American judge Tom McMillen (born 1952), American basketball player and politician Walter McMillen (1913–1987), Northern Irish footballer William L. McMillen (1829–1902), American physician and politician

See also Moore-McMillen House, historic home on Staten Island, New York, United States McMillen High School, high school in Texas, United States