William Joseph Coyne (August 24, 1936 – November 3, 2013) was a Democratic member of the United States House of Representatives from Pennsylvania from 1981 to 2003.

After completing his military service, he set up a private accounting firm.

Coyne was elected to Congress in 1980, succeeding 24-year incumbent William S. Moorhead in a district taking in most of Pittsburgh.

He was a longtime member of the United States House Committee on Ways and Means In 2002, Coyne's district was combined with the district of Mike Doyle, a somewhat more moderate Democrat.

Coyne died at the age of 77 on November 3, 2013, two months after falling and sustaining head injuries.