Ballycowan or Ballycowen () is a barony in County Offaly (formerly King's County), Ireland.
Ballycowan derives its name from Ballycowan Castle (near Tullamore) and the townland of Ballycowan (Irish Baile Mhic Comhainn, "settlement of Mac Comhainn").
Ballycowan is located in north County Offaly, around the valleys of the Clodiagh River and Silver River.
Ballycowan was part of the territory of the àMaolmhuaidh (O'Molloy) sept of the Southern UàNéill. The UàShuanaig (Fox?) sept is cited here near Rathan.
Below is a list of settlements in Ballycowan: