Left back George McMillan played for Ulster and Linfield before joining Belfast Distillery in 1902. In his first season with the club Distillery won the Irish League Championship and Irish Cup double, and McMillan was called up for Ireland, winning his first cap against England in a 4-0 defeat at Molineux in February 1903 and a further cap in a 2-0 win over Wales in Belfast the following month. He also won Irish League honours, first representing them in a 2-1 defeat to The Football League at Valley Parade, Bradford in October 1903, and being selected again in a 2-0 defeat to the same opponent in October 1904 at Grosvenor Park, Belfast. He also won the Irish League Championship (although it was shared, with Distillery in 1906, as well as a further Irish Cup win in 1905. Additionally he won the County Antrim Shield in 1903 and 1905, and The City Cup in 1905. He finished his career with Ulster Rangers joining them in 1908.