William McMillan (died 1991) was an Irish footballer who played for Belfast Celtic, Ballymena United and Crusaders.
Other members of the touring party included Aherne, Lawler, Campbell, guest player Mick O'Flanagan and manager Elisha Scott.
This team was basically a Great Britain XI and featured, among others, Matt Busby, Stanley Matthews, Tommy Lawton and Stan Mortensen.
He was one of several players born in Northern Ireland who benefited from the FAI's attempts to establish an all-Ireland influence.
In June 1946 when the FAI organised an Iberian tour, McMillan, together with Jackie Vernon, Jimmy McAlinden and Paddy Sloan, was one of four Northern Irish players called up.