Castletown
Castletown may refer to:
- Castle town, a settlement built adjacent to or surrounding a castle
 
Places
Australia
- Castletown, Western Australia, a suburb of the remote town of Esperance
 
Republic of Ireland
- Castletownroche, County Cork
 - Castletown, County Cork (disambiguation), several townlands and villages
 - Castletown, County Laois
 - Castletown, County Limerick, a townland and village in County Limerick
 - Castletown House, County Kildare
 - Castletownbere, County Cork
 - Castletown-Geoghegan, County Westmeath
 - Castletown, County Wexford
 - Castletown Kilpatrick, County Meath
 
Isle of Man
United Kingdom
- Castletown, Cheshire
 - Castletown, Dorset
 - Castletown, Highland, Scotland
 - Castletown, Penrith, Cumbria
 - Castletown, County Antrim, a townland in Islandmagee, County Antrim, Northern Ireland
 - Castletown, County Tyrone, a townland in Carnteel parish, County Tyrone, Northern Ireland
 - Castletown, Sunderland
 - RAF Castletown, Scotland
 
Other uses
- Castletown (horse), a New Zealand Thoroughbred racehorse
 - Castletown, County Mayo, the fictional setting of the mockumentary Hardy Bucks