Cantwell's Castle is a tower house located in the townland of Sandfortscourt in County Kilkenny, Ireland.

[1] Cantwell's Castle is situated in the southern part of the townland of Sandfordscourt, formerly known as Cantwellscourt, approximately 7.5km from Kilkenny City.

[4] At the time, surnames as such did not exist, so that spelling variations of "Cantwell" also include "Conteville", with "Cantuell" being the oldest form.

He died in 1701, is buried in St. Canice's Cathedral and was succeeded by his son Thomas Sandford[13] who was mayor of Kilkenny in 1723.

[16] Nothing remains in situ of the (presumably) manor house Cantwell's Court apart from a cobble-stoned courtyard discovered by the current owner.

The limestone-built castle sits on a partly surviving bawn,[18][19] the court-yard wall having been almost completely dismantled by 18th century farmer of the land Thomas Cahill.

The third floor (now floorless) contained the main accommodation with another fireplace, two ogee-headed windows and a recess in the south wall which is known as leabha chaol cruadh an Channtulaigh[7][13] or the hard, narrow bed of Cantwell.

The last floor is the attic, entered through a square-headed door and only accessible crossing the main hall,[18][24] now floorless.

A drawbar slot discovered by a family member of the present owners, stranded in Ireland during the first COVID lockdown, suggests a gate and thus maybe access from a road to the southwest.

Another road connecting the castle with the Sandfordscourt Road to the east from left of the house now called "Castle View" is lost, but traces can still be made out in satellite view in the Court Field, and there are four old trees suggesting an entrance into the avenue in the Court Field.