William Thomas Jr. (disambiguation)
William Thomas Jr. (1947–2020) is an American actor.
William Thomas Jr. may also refer to:
- William Thomas Jr. (child actor) or Billie "Buckwheat" Thomas (1931–1980), American actor
 - William A. Thomas Jr. or Bill Thomas (born 1947), American politician from Alaska
 - William Garfield Thomas Jr. (1916–1942), American naval officer
 - William S. Thomas Jr. (1901–1986), American Episcopal bishop
 - William W. Thomas Jr. (1839–1927), American diplomat and politician from Maine