The official name for the town is ‘Kilcullen Bridge’, to distinguish it from ‘Old Kilcullen’, a hill and settlement about 2 miles outside of town which was the scene of one of the bloodiest battles in the 1798 rebellion against English occupation.
Kilcullen is situated on the Naas/Athy and Kilkenny road and stretches half a mile each side of the bridge which is situated in the centre of the village. Prior to the building of the bridge in 1319, the main settlement had been at Old Kilcullen. Old Kilcullen was once the site of a monastery and the remains of a church, a round tower and 3 crosses are still in existence in the Old Kilcullen area.
In 1841, Kilcullen had a population of 1,056. In 1986, this had grown to 1,817, whilst in 1996 it had fallen to 1,682. According to the 2011 census Kilcullen has a population of 3,252.