J. J. Wolf (born December 21, 1998, in Cincinnati) is an American tennis player who rose through the college ranks at Ohio State, earning Big Ten Player of the Year in 2019 before turning professional that summer. He made a major breakthrough at the 2020 US Open by reaching the third round—beating Guido Pella and Roberto Carballés Baena—before falling to Daniil Medvedev, though his momentum was halted in 2021 by two hernia operations that sidelined him for seven months. Wolf made a strong comeback in 2022, securing his first ATP Tour final and defeating top-25 player Lorenzo Sonego, which helped him reach a career-high world No. 39 ranking in February 2023. Along the way, he has captured six ATP Challenger Tour singles titles, including victories in Champaign in 2019 and Nouméa in 2020. He also boasts a notable athletic pedigree as the grandson of former NBA coach Charles Wolf.