Augusta married her cousin, Lt. Colonel George Leigh (1771–1850), son of General Charles Leigh (1748–1815) and his wife, Frances Byron, her paternal aunt. She had seven children by him. Richard Temple-Nugent-Brydges-Chandos-Grenville, 1st Duke of Buckingham and Chandos, noted the wedding with disdain in his diary: "Poor Augusta Leigh marries today! Poor thing! I pity her connecting herself with such a Family, and such a fool! However she has nobody to blame but herself." The marriage turned out unhappily, because he fell into dissolution and gambled away all his money. At the end, he left his wife and children nothing but debts.