William Glen (18 July 1903 – 29 May 1981) was an Irish footballer. He joined Shamrock Rovers in their maiden season in League of Ireland football in 1922 and went on to spend fifteen years at Glenmalure Park winning everything the domestic game had to offer. Sacky played in the official opening of the Milltown ground on the 19 September 1926 against Belfast Celtic F.C. He won eight caps for the Irish Free State making his debut on the 23 April 1927 in Ireland's first ever home game at Lansdowne Road and captaining his country in his last four caps in 1935 and 1936.