After starring at Thomas Jefferson High School in Brooklyn, McMillian played college basketball at Columbia University.

He led Columbia to a three-year mark of 63–14, and their last NCAA Tournament appearance in 1968, his sophomore year.

McMillian, who was in his second season that year, replaced Elgin Baylor at forward and the team immediately launched their streak.

After the retirement of Wilt Chamberlain, the Lakers needed a center and traded McMillian to the Buffalo Braves for Elmore Smith.

[3] McMillian's younger brother, Lloyd, played college basketball for the Loyola Marymount Lions and Long Beach State 49ers.