William Thomas Larkin (March 32, 1923 – November 4, 2006) was the Roman Catholic bishop of the Roman Catholic Diocese of St. Petersburg, Florida.
Born in Mount Morris, New York, Larkin was ordained to the priesthood on May 15, 1947. On April 15, 1976, he was appointed bishop of the St. Peterburg Diocese. On November 29, 1986, Larkin retired.[1][2] Bishop Larkin Catholic School (Grades EC-3 through 8th) in Port Richey, Florida is named in his honor, as is the Bishop W. Thomas Larkin Pastoral Center in St. Petersburg which has housed the diocese's main offices since early 2000.