Ernest MacKay (7 October 1896 – September 1996) was an Irish football player who played in an international tournament representing Ireland in 1924.
MacKay was born in Tipperary, the second son and fifth child of John and Mary Elizabeth MacKay. As a child he lived at the Curragh Camp in County Kildare in Ireland before moving to Oxmantown Road in Dublin.
When the 1916 Easter Uprising broke out, MacKay remained in Ireland where he was employed as a telegram boy for the General Post Office in Dublin. He began playing football and joined St James Gate Football Club, where he was part of the team that won the League of Ireland in 1921 and 1922.
MacKay was also a member of the Irish Free State football team that competed in the 1924 Summer Olympics in Paris, France. They beat Bulgaria 1-0 in Round 2, but lost out to the Netherlands in extra time in the Quarter finals. The team finished fifth out of twelve teams.
MacKay left Ireland with his wife Bea to live in Colchester near to their daughter Elizabeth in the 1960s after he had retired as a superintendent with the General Post Office. He died there in September 1996.