Clann Fhergail was a cantred located in County Galway, comprising the baronies of Moycullen and Galway, the parishes of Oranmore and Ballynacourty and Rahoon.
Crichaireacht cinedach nduchasa Muintiri Murchada is a tract dating to the reign of its overlord, Flaithbertaigh Ua Flaithbertaigh (died 1098, King of Connacht from 1092-1098). It lists the main families and their estates within Clann Fhergail. The first listed was the family of Halloran.