Gerald Joseph Monaghan (February 27, 1915 – June 2, 1973) was a Canadian politician, who represented the electoral district of Sudbury in the Legislative Assembly of Ontario from 1955 until 1959.
He was a member of the Ontario Progressive Conservative Party.
He was born in Thurso, Quebec in 1915.Prior to his election to the legislature, Monaghan was a city councillor in Sudbury.