Clonony, Tudor tower house in County Offaly, Ireland.

Clonony is a three-storey tower house of the MacCoughlan clan in County Offaly, between the River Brosna and the Grand Canal. Its fifty-foot tower, an Irish National Monument, has a west entrance with a machicolation above it, a fire-proof vault over the ground floor, a spiral stair, gun-loops and a garderobe. A nineteenth-century bawn wall with two square corner towers surrounds it, with gardens and a moat.

Clonony Castle is a Tudor tower house built by the MacCoughlan clan before 1519, when John Óg MacCoghlan ceded it to Henry VIII; the king then granted it to Thomas Boleyn, whose daughter Anne he intended to marry. The MacCoghlans forfeited it during the Nine Years' War, and from 1612 to about 1620 it was held by Matthew de Renzi, a London cloth merchant from Cologne who compiled the first English-Irish dictionary. Mary and Elizabeth Boleyn, second cousins of Queen Elizabeth I, lived out their lives here; their limestone grave slab was found in 1803 about 100 yards from the castle.

The name Clonony comes from the Irish Cluain Damhna Beag. Mary and Elizabeth Boleyn, second cousins of Queen Elizabeth I, lived out their lives in the castle; their limestone grave slab, found in 1803 about 100 yards from the castle, records them as daughters of Thomas Bullyn. The castle is open free of charge, without fixed hours, and the owners encourage tours.

The castle is open to the public free of charge, with no fixed opening hours; the owners try to keep it open and welcome tours. The tower stands three storeys high, entered through a doorway in the west wall, and a spiral stair leads to the upper floors. The bawn wall with its two square corner towers was rebuilt in the nineteenth century.

The castle was occupied from 1612 to about 1620 by Matthew de Renzi, a London cloth merchant from Cologne who, according to his tombstone in Athlone, compiled the first English-Irish dictionary. He acquired Clonony after the MacCoghlans forfeited it during the Nine Years' War.