Background
Cotter was born in Milan, Italy, the son of a Church of England rector in Ireland.
Cotter was born in Milan, Italy, the son of a Church of England rector in Ireland.
He was educated at private schools in the south of Ireland, and came to Canada in 1890.
Cotter worked as an accountant, and was for fifteen years the chief accountant of Winnipeg, Manitoba. He served as a school trustee from 1912 to 1915, was a councillor in the municipality of Saint James in 1924, and served as its reeve in 1925. From 1925 to 1927, he was the representative of Saint James on the Winnipeg Municipality Suburban Board.
He served as reeve of Saint James a second time in 1928-1929.
From 1916 to 1919, Cotter served overseas in World War I as a lieutenant with the 108th Battalion. He was later transferred to the C.A.P.C.
He was elected to the Manitoba legislature in the 1927 provincial election, defeating Independent Labour Party candidate Richard B. Russell.
The Conservatives became the leading opposition party after this election, and Cotter served with his party on the opposition benches. He did not run for re-election in 1932.
He died at Saint James, Manitoba on 30 September 1937.
He was a member of the Conservative Party.