Woulfe believes they were a branch of McDermott in Roscommon. These two, along with O'Connor, may have been of the same clan.

A different Crowley family was seated in Cork, with ancestral name Ó Croghallaigh. It could have some association with the O'Mahonys. They were in the area inhabited by Ó Sealbhaigh (Shealy or Sheily) between Dunmanway and Bandon in East Carbery.

After putting down a rebellion of Carbery men in 1283, including Carbery McCarthy, Domhnall McCarthy, King of Desmond, reached out to force migration into the Carberies in order to scatter the Carbery men. Uí Chruadhlaoich of Connacht may have been among the clans to whom Domhnall McCarthy reached. Among the earliest references of the Crowley name in Cork is Ragnall, who was slain by Eógan (Eugene) McCarthy later in 1283.