search for the origin of the name McGarrah family name.Variations found include Geary, Gara, O'Gara, O'Geary, Gearie, Gearey and many more. First found in County Sligo , where they were Chiefs of Coolavin aad Sliabh Lugha. [ 1 ] The surname also spelled Gara, O'Gara, and Gerry is descended from Tiachleach,