James O'Hara, 2nd Baron Tyrawley

Field Marshal James O'Hara, 2nd Baron Tyrawley and 1st Baron Kilmaine, PC (1682 – 14 July 1774), was an Irish officer in the British Army. After serving as a junior officer in Spain and the Low Countries during the War of the Spanish Succession, he went on to become British ambassador to Lisbon establishing a close relationship with King John V there. He undertook a tour as British ambassador to Saint Petersburg before becoming Governor of Gibraltar where he set about improving the fortifications. He was briefly commander of British troops in Portugal during the Seven Years' War but was replaced within a few months. During his military career, he was colonel of eight different regiments.