General Thomas Garth (1744 – 18 November 1829) was a British Army officer and chief equerry to George III.
Garth was the son of John Garth (1701–1764), Recorder and MP for Devizes, and Rebecca, daughter of John Brompton and granddaughter of Sir Richard Raynsford, Lord Chief Justice of the King's Bench.
Garth rented Ilsington House at Puddletown, which was often visited by the royal family en route for Weymouth.
He named his residuary legatee as his nephew, Captain Thomas Garth RN (1781–1841) of Haines Hill, Berkshire, the son of General Garth's older brother, Charles (1734–1784) who was an MP and Government Agent for South Carolina, Georgia and Maryland.
Another brother, George Garth (abt 1733–1819) was a British General in American Revolutionary War, and Colonel of the 17th Regiment of Foot.