John Lanneau "Johnny Mac" McMillan (April 12, 1898 – September 3, 1979) was a United States Representative from South Carolina. Born on a farm near Mullins, he was educated at Mullins High School, the University of North Carolina, as well as the University of South Carolina Law School and National Law School in Washington, D.C. He was selected to represent the United States Congress at the Interparliamentary Union in London in 1960, and in Tokyo in 1961. He resided in Florence, South Carolina, where he died in 1979; interment was in the McMillan family cemetery, Mullins.