Daniil Sergeyevich Medvedev (Russian: Даниил Сергеевич Медведев; born 11 February 1996) is a Russian professional tennis player. He is currently ranked world No. 1 by the Association of Tennis Professionals (ATP). He has won 14 ATP Tour singles titles, including the 2021 US Open and 2020 ATP Finals. In the former, Medvedev defeated then-world No. 1 Novak Djokovic in the final to deny him the Grand Slam. In the latter, he became the first and only player to defeat the top three ranked players in the world en route to the year-end championship title. He has also won four Masters 1000 titles and contested four major finals.