William Cotter (born 10 February 1943) is a former Irish Fine Gael politician A school principal before entering politics, he was elected to Dáil Éireann on his first attempt, when he stood in the Cavan–Monaghan constituency at the 1989 general election to the 26th Dáil. He lost his seat at the 1992 general election, but at the subsequent elections to the 20th Seanad he was elected on the Labour Panel. He was an elected member of Monaghan County Council for the Carrickmacross Electoral Area from 1985 until 1999.