One So Wonderful (4 May 1994 – February 2012) was a British Thoroughbred racehorse and broodmare. A temperamental filly who was sometimes difficult to train, she is best known for winning the International Stakes in 1998. After winning on her only appearance as a two-year-old she won both her races in 1997 including the Sun Chariot Stakes. She was beaten on her debut as a four-year-old but then won the Golden Daffodil Stakes before defeating male opposition in the International Stakes.