Sun Briar (foaled 1915 in France) was a Thoroughbred racehorse retrospectively named the American Champion Two-Year-Old Colt of 1917 and the American Champion Older Male Horse of 1919 by writers from The Blood-Horse magazine. He was a son of , the 1911 Champion sire in Great Britain who also sired Epsom Derby winner Sunstar. Sun Briar was out of the mare Sweet Briar, the daughter of St. Frusquin, a multiple winner of top-level races including the 1896 British Classic and the 2,000 Guineas Stakes. St. Frusquin was also a leading sire in Great Britain and Ireland in 1903 and the Leading broodmare sire in Great Britain & Ireland in 1924.