McMillin is a surname. Notable people with the surname include:
Benton McMillin (1845–1943), Governor of TennesseeBo McMillin (1895–1952), American football coachChallace McMillin, American football coach at James Madison UniversityCorky McMillin (1929–2005), American racerDavid McMillin (born 1984), American singerGeorge McMillin (1889–1983), 38th and final Naval Governor of GuamJames McMillin (1914–2005), American Olympic rowerJohn Ernest McMillin (1884–1949), member of Canadian House of CommonsJudson McMillin (born 1977), member of the Indiana House of Representatives