Felix O'Neill (died 1709)

Felix O'Neill (d. 1709) was an Irish Jacobite soldier and landowner. He was a descendant of the O'Neill dynasty of Ulster and played a prominent role in the Williamite War in Ireland.

Details of Felix O'Neill's early life are somewhat scarce, but he was part of the landowning gentry in County Clare. He held the rank of Colonel and commanded a regiment in the Jacobite army of James II. During the Williamite War, he fought in several key battles, including the Siege of Limerick in 1690 and the Battle of Aughrim in 1691.

Following the Jacobite defeat at Aughrim, O'Neill was amongst those who retreated to Limerick. He was prominent in the defense of Limerick during its second siege. After the Treaty of Limerick in 1691, O'Neill, like many Jacobite officers, was offered the choice of entering into foreign service or remaining in Ireland under Williamite rule.

O'Neill chose to go into exile. He entered the service of France and served in the Irish Brigade of the French army. He died in France in 1709.

His lands in County Clare were forfeited following his support of the Jacobite cause.