Colonel Alexander Montgomery (1667 – 25 March 1722) was an Irish soldier and MP.
His father was Major John Montgomery of Crogan, County Donegal.
Alexander joined the British Army and was promoted a captain of the Inniskilling Dragoons in 1689, a major in 1704 and a lieutenant colonel in 1706.
Montgomery died on 15 March 1722 and his will dated 28 August 1721 was proved on 6 July 1722.
He was a Captain in ye 3rd regiment, and now in 1704 a major because it was not reduced: married Captain Coles (in ye County of Monaghan) his daughter and heiress, and now lives within two miles of Monaghan town, and hath a son, this gentleman hath a good Estate, and is a thriving man and a great tenant to ye present Duke of Ormond".