Thomas Henry Barclay (12 October 1753 – 21 April 1830) was an American lawyer who became one of the United Empire Loyalists in Nova Scotia and served in the colony’s government.
Barclay came from a prominent New York family, the son of the Reverend Henry Barclay, an Anglican clergyman, and Mary Rutgers, the daughter of a wealthy brewer. After attending King’s College (later Columbia University), he studied law with John Jay and was called to the bar in 1775. In the same year, he married Susan DeLancey. Shortly afterwards, his career was interrupted by the beginning of the American Revolutionary War. Barclay served with distinction in the British forces throughout the war and, with the confiscation of his New York property and having been named specifically in a Bill of Attainder in that state, he chose to join the loyalists heading to Canada.
After considering New Brunswick, Barclay opted for Nova Scotia where the forces were given land grants. At one point, he had moved to Annapolis Royal and began a law practice. He was elected to the 6th General Assembly of Nova Scotia representing Annapolis County in 1785 while Edmund Fanning was governor. The next year, John Parr became governor. In 1793, Barclay was elected for Annapolis Township and served as speaker for the assembly. He also served as lieutenant-colonel in the colony’s militia and was boundary commissioner for the British when the border between the United States and New Brunswick was settled in Jay’s Treaty. Although he was appointed to the Council for Nova Scotia in 1799, he was given the post of British consul general in New York City later that year. Following the War of 1812, he became a member of another boundary commission dealing with another section of the border with the United States.
In 1822, he settled at a country home on Manhattan. He died there in 1830 and was buried in the Bowery.