one. Accordingly, research into the name O'Geary revealed spelling variations , including 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,