James O'Hara, 2nd Baron Tyrawley and Kilmaine, PC (1682 - July 14, 1774) was a British military officer. He was given the rank of field marshal on June 10, 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.