— Shane Carragh, [58]

— Rory Oge, [62], [145]

— Manus, [342]

Ochiltree, Lord, [111]

O’Coffie, called bishop, [106]

O’Connolly, Owen, discoverer of the 1641 plot, [319]-[321], [330], [336]

O’Connor clan, [92]

O’Daly’s bridge, [340]

O’Dempsey, [92]

O’Devany, Cornelius, titular bishop of Down, executed, [98]