Castlelost West is a townland in County Westmeath, Ireland.[1] The townland is located in the civil parish of the same name.[2] The R446 regional road runs through the south of the area. The townland of Castlelost lies to the east and contains the town of Rochfortbridge. The town of Tyrrellspass stands to the west of the townland.
The townland is bordered by Castlelost to the east, Clontytallon, and Kilbride to the north, Gneevebane, and Oldtown to the south, and Piercetown to the west.