Naomi Osaka is a Japanese professional tennis player. She has been ranked world No. 1 in singles by the Women's Tennis Association (WTA) and is the first Asian player to hold the top ranking in singles. Osaka is a four-time Grand Slam singles champion, with two Australian Open and two US Open titles. Her seven titles on the WTA Tour also include two at the Premier Mandatory level. At the 2018 US Open and the 2019 Australian Open, Osaka won her first two major titles in back-to-back tournaments. She was the first woman to win successive major singles titles since Serena Williams in 2015, and the first to win her first two in successive majors since Jennifer Capriati in 2001.
Osaka was born in Japan to a Haitian-American father and a Japanese mother. She has lived and trained in the United States since age three. She came to prominence at age 16 when she defeated former US Open champion Samantha Stosur in her WTA Tour debut at the 2014 Stanford Classic. Two years later, she reached her first WTA final at the 2016 Pan Pacific Open in Tokyo to enter the top 50 of the WTA rankings. Osaka made her breakthrough into the upper echelon of women's tennis in 2018 when she won her first WTA title at the Indian Wells Open. Later that year, she defeated 23-time Grand Slam singles champion Serena Williams in the final of the US Open to become the first Japanese player to win a major singles title. From 2018 to 2021, Osaka won a major singles title in four consecutive years. In mid-2021, suffering from depression and other issues, Osaka retired from the French Open, dropped out of Wimbledon, and lost early at the US Open. She closed down the rest of her tennis season to focus on family and health. After taking another hiatus in 2023 due to maternity leave, Osaka has returned to competition in 2024.
Osaka is one of the world's most marketable athletes, having been ranked eighth among all athletes in endorsement income in 2020. She was also the highest-earning female athlete of all time by annual income that year. Osaka has gained significant recognition as an activist, having showcased support for the Black Lives Matter movement in conjunction with her matches. She was named one of the 2020 Sports Illustrated Sportspersons of the Year for her activism largely as part of her US Open championship run, and was also included on Time's annual list of the 100 most influential people in the world in 2019, 2020 and 2021. Moreover, she was the 2021 Laureus World Sportswoman of the Year. At the 2020 Tokyo Olympics, she became the first tennis player to light the Olympic cauldron during the opening ceremony. On the court, Osaka has an aggressive playing style with a powerful serve that can reach 201 kilometers per hour (125 mph).