Serena Williams is an American professional tennis player who is widely regarded as one of the greatest athletes of all time. She has won 23 Grand Slam singles titles, the most by any woman in the Open Era and the second-most by any player in history. She has also won 14 Grand Slam doubles titles (with her sister Venus) and 2 Olympic gold medals. Williams is the only player to have won a Grand Slam singles title while pregnant. She is also the highest-earning female athlete of all time, with career prize money of over $90 million.