There have been two Baronetcies created for members of the McMahon family, both in the Baronetage of the United Kingdom. One creation is extant as of 2007.
The McMahon Baronetcy, of Dublin, was created in the Baronetage of the United Kingdom on 6 May 1815 for William MacMahon who was Master of the Rolls in Ireland. The title became extinct on the death of the fourth Baronet in 1926.
The McMahon Baronetcy, of Ashley Manor, was created in the Baronetage of the United Kingdom on 7 August 1817 for John McMahon, Member of Parliament for Aldeburgh from 1802 to 1812 and Private Secretary to George IV from 1811 to 1817. He was the brother of the first Baronet of the 1815 creation. McMahon was succeeded according to a special remainder by his second brother, the second Baronet. He was a General in the Army and served as Commander-in-Chief of the Forces at Bombay.
The family surname is pronounced "McMahn".