He was born November, 1728 in Edinburgh, Scotland, the son of Gilbert Elliot. He arrived in Pennsylvania in 1746 as an apprentice and established himself as a trader. In 1762, he was elected a member of the board of trustees of the College of Philadelphia. In 1763, he was appointed collector of the port of New York and receiver general of New York. In 1764 he was appointed to the Province of New York executive council.
During the American Revolution he remained a Loyalist. A few days after the declaration of independence he left New York City for Perth Amboy for his safety. He returned to New York City after the British reoccupation. On May 1, 1777 he was appointed the head of the military court of police and on July 17 the superintendent of all imports and exports. In 1780 he was appointed lieutenant governor of the Province of New York. In 1783 he was part of the delegation that met with George Washington. He was the acting governor from April, 1783 to November. Elliot left for Scotland in December, 1783.
When he returned to Scotland he held no public office. He died at home on May 25, 1797 at Mount Teviot, Jedburgh.
