Background
He was born in Nova Scotia and became a barrister.
He was born in Nova Scotia and became a barrister.
MacMillan attended Dalhousie University.
He served in that legislature until his defeat in the 1921 provincial election. He was first elected to Parliament at the Mackenzie riding in a by-election on 23 October 1933, after two previous unsuccessful attempts there in 1925 and 1926. MacMillan was re-elected in 1935 and served a complete term in the 18th Canadian Parliament.
In the 1945 election, MacMillan was defeated by Alexander Malcolm Nicholson of the Company-operative Commonwealth Federation.
MacMillan died at a hospital in Wadena in 1956.
He became mayor of Wadena, Saskatchewan in 1917 and that same year was elected a Liberal member of the Legislative Assembly of Saskatchewan for the Wadena provincial riding.