Fauntleroy was born in Clarke County, Virginia to Joseph Fauntleroy (of Richmond County, Virginia) and his wife Elizabeth ("Betsy") Fouchee Fauntleroy (of Richmond, Virginia).^[1]

Although only 17 years old, he was commissioned a lieutenant in the U.S. Army during the War of 1812.^[2]

After the war, Fauntleroy studied law in Winchester, Virginia, then practiced law in Warrenton, Virginia.^[1] He married Ann Magdelin Magill, daughter of Col. Magill of Wincheser. They had two daughters and two sons who would survive the American Civil War: Thomas Turner Fauntleroy Jr. (1823–1906), Mary Thurston Fauntleroy Barnes (1824–1912), Katherine Knox Fauntlerosy Whittlesey (1834–1906), and Archibald Magil Fauntleroy (1836–1886). His firstborn son, C.N. Fauntleroy, joined the Confederate Navy.

He was elected to the Virginia House of Delegates from Fauquier County, Virginia in 1823 for a single term, serving alongside John Marshall Jr., who had likewise ousted an incumbent delegate but who would continue to serve in the next session.^[3][4]

Commissioned a major of dragoons on June 8, 1836, Fautleroy served in the Second Seminole War.^[1] Detached from Major General Zachary Taylor's main force in 1835, he held native Americans in check on the Texas frontier. He was promoted to lieutenant colonel, Second Regiment of Dragoons, on June 30, 1846, and ordered to join General Taylor's force during the Mexican–American War at the Rio Grande. Later, he commanded the cavalry of Major General Winfield Scott's army in the campaign to capture Mexico City.^[1]

In 1849 he assumed command of the First Regiment of Dragoons, commanding troops on frontier duty in Texas. His next assignment commanded the Post at Mission San Diego de Alcalá at San Diego, which led to his promotion to colonel on July 25, 1850. He then commanded Fort Vancouver in Oregon Territory. During this time, three of his brothers died: Robert Henry Fauntleroy in Galveston Texas in 1849, Leroy D. Fauntleroy in Pensacola, Florida in 1853 and William M. Fauntleroy in Adams County, Mississippi in 1854.

During the winter of 1854–1855, Col. Fauntleroy campaigned against the hostile Utes in the Rocky Mountains and in 1858 made another mid-winter campaign against the Apache in New Mexico.^[5] He also led several expeditions against the Apaches, accompanied by scout Kit Carson. From 1859–1861 Col. Fauntleroy commanded the Department of New Mexico.^[6][7]

While Col. Fauntleroy fought in the West, his son and namesake had become a lawyer and followed his father's example by winning election to the Virginia House of Delegates, albeit for Frederick County. After the Battle of Fort Sumter that began the American Civil War and Virginia's secession in April 1861, Fauntleroy resigned his U.S. Army commission in May 1861 and returned to his native Commonwealth. Governor of Virginia John Letcher appointed Fauntleroy as brigadier general of the Provisional Army of Virginia. However, by the following month, the Confederate States Army had been organized and the Provisional Army of Virginia was merged into it. Fauntleroy refused to accept a CSA commission, despite General Samuel Cooper offering such on July 9, 1861.^[8] He was relieved of that rank on his request on August 25, 1861, having never held Confederate rank.^[8]

After the war, the retired Fauntleroy lived in Opequon, Virginia near Winchester with his son Thomas' family.^[9]

Fauntleroy's eldest son, C. M. Fauntleroy was a U.S. Navy officer who joined the Confederate Navy and commanded the CSS Rappahannock. His second son, also named Thomas T. Fauntleroy, became a Virginia lawyer and politician and after the war a judge of the Virginia Supreme Court of Appeals. Another son Archibald Magill Fauntleroy became a surgeon in the Confederate army and later a physician. A daughter, Mary Thurston Fauntleroy, married Surgeon General of the United States Army Joseph Barnes.^[10]

Although Fauntleroy lived in Winchester with his son Thomas' family in 1880,^[11] he died in Leesburg, Virginia on September 12, 1883, and was buried at Mount Hebron Cemetery in Winchester.^[12]

• Allardice, Bruce S. Confederate Colonels: A Biographical Register. Columbia: University of Missouri Press, 2008. ISBN 978-0-8262-1809-4.
• Allardice, Bruce S. More Generals in Gray. Baton Rouge: Louisiana State University Press, 1995. ISBN 978-0-8071-3148-0.
• Wilson, J. G.; Fiske, J., eds. (1900). "Fauntleroy, Thomas Turner" . Appletons' Cyclopædia of American Biography. New York: D. Appleton.
• WO1 Mark J. Denger, "Post at Mission San Diego de Alcalá", California Center for Military History. Note 6
• Eicher, John H., and David J. Eicher, Civil War High Commands. Stanford: Stanford University Press, 2001. ISBN 978-0-8047-3641-1.
• Army biography for Joseph Barnes Archived 2010-12-03 at the Wayback Machine
• Sifakis, Stewart. Who Was Who in the Civil War. New York: Facts On File, 1988. ISBN 978-0-8160-1055-4.
• Utley, Robert M. Frontiersmen in Blue: The United States Army and the Indian, 1848–1865. New York: Macmillan, 1981. ISBN 978-0-8032-9550-6. First published: Lincoln, NE: University of Nebraska Press, 1967. (Pages 210–349 are on the Civil War period.)