Gets it name from "Castleton" the residence of the Thompson family. The castellated residence named "Castleton" was erected to take the place of an earlier residence named Jennymount. In an account of a demonstration, April 15, I848, the residence is called "Castlemount". (John J. Marshall, Origin of Some of Belfast's Street-Names, p. 6)
On the application of the owners, your committee have named two new streets off' York Road " Alexandra Park Avenue and "Castleton Avenue’; also two new streets off Springfield Road, "Crocus Street" and Violet Street.” Belfast News-Letter - Tuesday 03 February 1891.