Castletown is a north-eastern suburb of Esperance, a town in south-eastern Western Australia.

Its local government area is the Shire of Esperance.

[4] Castletown is located 4 kilometres (2 mi) northeast of Esperance's central business district.

[6] Castletown residents had a median age of 34, and the median individual income was $480 per week compared with $454 per week in the Esperance region.

The population of Castletown was predominantly Australian-born - 83.5% as at the 2006 census and at the 2006 census, 3.9% of residents identified as Indigenous Australians.