Williamstown
- Ballyloughloe
- Bimbia
- Blackrock, Dublin
- Electoral district of Williamstown
- Foyran (civil parish)
- Frytown
- Mayne, County Westmeath (civil parish)
- Piercetown, County Westmeath (civil parish)
- RAAF Base Williamtown
- Strange, Ontario
- Williamson (disambiguation)
- Williamston (disambiguation)
- Williamstown (CDP), Massachusetts
- Williamstown (CDP), Vermont
- Williamstown Beach railway station
- Williamstown Township, Michigan
- Williamstown railway line
- Williamstown railway station, Melbourne
- Williamstown, County Galway
- Williamstown, County Limerick
- Williamstown, Indiana
- Williamstown, Kansas
- Williamstown, Kentucky
- Williamstown, Massachusetts
- Williamstown, New Jersey
- Williamstown, New York
- Williamstown, Ohio
- Williamstown, Ontario
- Williamstown, Pennsylvania
- Williamstown, Rhondda Cynon Taf
- Williamstown, South Australia
- Williamstown, Vermont
- Williamstown, Victoria
- Williamstown, West Virginia
- Williamstown, Western Australia
- Williamstown, Wisconsin
- Williamtown, New South Wales