Wesley Barbossa So (born October 9, 1993) is an American–Filipino chess grandmaster, a three-time U.S. Chess Champion, and the first World Fischer Random Chess Champion. He is also a three-time Philippine Chess Champion. On the March 2017 FIDE rating list, he was ranked number two in the world and had an Elo rating of 2822, making him the fifth-highest-rated player in history. In 2019, So said his favorite form of chess is chess960 (also known as Fischer random chess). Later that year, So became the inaugural World Fischer Random Chess Champion after defeating Magnus Carlsen to win the FIDE World Fischer Random Chess Championship. A former chess prodigy, So became the youngest player to pass a 2600 Elo rating in October 2008, breaking the record previously held by Carlsen. This record has since been broken by Wei Yi, John M. Burke and Yağız Kaan Erdoğmuş. In early 2013, So passed 2700 and in January 2017 he became the 11th player to pass 2800 Elo. So represented the Philippines until transferring to the United States in 2014. He won the 2015 Bilbao Chess Masters, the 2016 Grand Chess Tour title after claiming victory in the Sinquefield Cup and London Chess Classic, the 2017 Tata Steel Masters, the 2021 Grand Chess Tour, and the 2025 Sinquefeld Cup.