Williamstown or Williamtown is the name of several places in the world:
- Australia
- Williamtown, New South Wales
- RAAF Base Williamtown, New South Wales
- Williamstown, South Australia
- Williamstown, Victoria
- Williamstown railway line
- Williamstown railway station, Melbourne
- Williamstown Beach railway station
- Williamstown, Western Australia, a suburb of Kalgoorlie
- Electoral district of Williamstown, an electoral district in Victoria
- Cameroon
- Williamstown, Bimbia, a historical village in the kingdom of Bimbia, now no longer in existence
- Canada
- Williamstown, Ontario
- the historical name of Strange, Ontario
- Ireland
- Williamstown, Ballyloughloe, townland in Ballyloughloe civil parish, barony of Clonlonan, County Westmeath
- Williamstown, County Dublin
- Williamstown, County Galway
- Williamstown, County Roscommon
- Williamstown, Foyran, a townland in Foyran civil parish, barony of Fore, County Westmeath
- Williamstown, Mayne, a townland in Mayne civil parish, barony of Fore, County Westmeath
- Williamstown, Piercetown, a townland in Piercetown civil parish, barony of Rathconrath, County Westmeath
- United Kingdom
- Williamstown, Rhondda Cynon Taf, Wales
- United States
- Williamstown, Indiana
- Williamstown, Iowa, alternative name for Frytown, Iowa
- Williamstown, Kansas
- Williamstown, Kentucky
- Williamstown, Massachusetts
- Williamstown, New Jersey
- Williamstown, New York
- Williamstown, Pennsylvania
- Williamstown, Vermont
- Williamstown, West Virginia
- Williamstown, Wisconsin
- Williamstown Township, Michigan
See also
- Williamston (disambiguation)
- Williamson (disambiguation)