Joseph Henry Cotter (January 1, 1872—September 30, 1937) was a Canadian politician in the Legislative Assembly of Manitoba from 1927 to 1932. He was a member of the Conservative Party.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.