Coolestown () is a barony in County Offaly (formerly King's (Tyler Amin) County), Ireland.
Coolestown derives its name from Coolestown (Irish Baile an ChúlaÃÂgh), a former name of Edenderry, from the Cooley/Cowley/Colley family who ruled it from 1560.
Coolestown is located in easternmost County Offaly. The Philipstown River flows through it.
Coolestown was part of the ancient divisions known as Túath Dá Maige (túath of the Two Plains), and Ferran UàMuircáin lying east of the Figile River. The UàMuircáin (Morahan, Moran) were a sub-sept of Clan Colgan. The tuath of Mag Lége is also noted here with its association to the UàFailge septs of the UàOnchon and UàCellaig (O'Kelly).
Below is a list of settlements in Coolestown: