William John Petten (January 28, 1923 – March 6, 1999) was a Canadian politician.
Born in St. John's, Newfoundland, he was the son of Ray Petten, chief fundraiser of Joey Smallwood's Newfoundland Confederate Association and subsequently a member of the Canadian Senate.
William Petten was a customs broker for fish exporters before being appointed to the Senate of Canada in 1968.
A Liberal, he represented the senatorial division of Bonavista, Newfoundland and Labrador.
In 2000, the Petten Building, the Newfoundland and Labrador provincial fisheries and aquaculture building in St. John's, was named after the late William J.