Sir Thomas McMahon, 2nd Baronet

Lieutenant-General Sir Thomas McMahon, 2nd Baronet (1779–1860) was a British Army officer.

He was the youngest son of John MacMahon, comptroller of the Port of Limerick, and his second wife Mary Stackpoole. He had a full brother, Sir William MacMahon, 1st Baronet, Master of the Rolls in Ireland, and a half-brother, Sir John McMahon, 1st Baronet, Private Secretary to the Prince Regent from 1811 to 1817.

While Thomas and William were both gifted men, their early careers were hampered by their relatively humble social origins, and there is little doubt that their half-brother's position greatly assisted in their rise to prominence.

John was the first of the McMahon Baronets of Ashley Manor: on his death in 1817 the title passed to Thomas by special remainder.

He married Emily Westropp and they had nine children, including General Sir Thomas Westropp McMahon, 3rd Baronet.

McMahon served in the Portuguese army in the Peninsular War and became adjutant-general in India. He went on to be Lieutenant-Governor of Portsmouth and General Officer Commanding South-West District in 1834 and became Commander-in-chief of the Bombay Army on 14 February 1840 retiring from that post on 8 April 1847.