On 23 December 1752[1] at St George's, Hanover Square, in London, Beauclerk married Jane Roberts (d. 16 Dec 1778[2]), daughter and heiress of Sir Walter Roberts, 6th Baronet of Glassenbury (1691–1745), and his wife, Elizabeth Slaughter (only daughter and heiress of William Slaughter, of Rochester, county Kent).[1] Jane Roberts died on 16 December 1778 without issue. On Beauclerk's death in 1786, his titles passed to his second cousin[1]George Beauclerk.