James O'Hara, 2nd Baron Tyrawley and 1st Baron Kilmaine, PC (1682 – 14 July 1774) was an Irish officer of the British Army. He was given the rank of field marshal on 10 June 1763. His father was Charles O'Hara, 1st Baron Tyrawley, a military officer as well.

O'Hara commanded the 7th Regiment of Foot, 4th Dragoon Guards, 2nd Horse Grenadier Guards, 3rd Horse Guards, 10th Regiment of Foot, 14th Regiment of Dragoons, 3rd Regiment of Dragoons, and the Coldstream Guards, successively.

His Portuguese-born illegitimate son Charles O'Hara also saw military service in the American War of Independence and the French Revolutionary Wars, rising to the rank of full general.