First Sergeant Thomas Hall Forsyth (December 17, 1842 – March 22, 1908) was an American soldier in the U.S. Army who served with the 4th U.S. Cavalry during the Indian Wars.

He received the Medal of Honor for gallantry against the Cheyenne Indians, rescuing his commanding officer and another wounded soldier, at the Powder River in Wyoming Territory on November 25, 1876.

He later enlisted in the United States Army in St. Louis, Missouri, and had a long and successful military career serving with 4th U.S. Cavalry on the Texas frontier.

While battling the Cheyenne at Powder River in the Wyoming Territory, on November 25, 1876, Forsyth took command of Company M when First Lieutenant John A. McKinney was mortally wounded.

As McKinney lay dying by the river, Forsyth and two other men, Sergeant Frank Murray and Corporal William J. Linn, remained at his side despite all being wounded themselves.