The N9 road from Dublin to Waterford previously passed through the village but upon completion of a motorway bypass in 2010, it was re-designated the R448.

Also, the oldest intact window in Western Europe can be found in the town, being part of the ruins of a Franciscan Monastery.

South Kildare Community Transport operate a route from Castledermot to Athy twice a day each way Mondays to Fridays inclusive.

Bus Éireann used to serve Castledermot more frequently, but the solitary Sunday evening journey was withdrawn in 2015.

There are several buses each day including Sunday linking the town to Carlow and Naas as well as villages such as Moone in the area.

5 km (3.1 mi) away is Kilkea Castle, once the residence of the Duke of Leinster, but now a hotel and health farm.

The castle was built by the English Norman Hugh de Lacy in 1180, and later passed to the Fitzgeralds.