After retiring from active naval service, Elliot followed a career in the Foreign Office. From 1830 to 1833, he was Protector of Slaves in Guiana. In 1834, he went to China as Master Attendant to the staff of Chief Superintendent Lord Napier. He became Plenipotentiary and Chief Superintendent from 1836 to 1841. From 1842 to 1846, Elliot was chargé d'affaires and consul general in the Republic of Texas. He served as Governor of Bermuda (1846–54), Governor of Trinidad (1854–56), and Governor of Saint Helena (1863–70). He was made a Knight Commander of the Order of the Bath in 1856.