Billie Jean King, also known as BJK, is an American former world No. 1 tennis player. King won 39 Grand Slam titles: 12 in singles, 16 in women's doubles, and 11 in mixed doubles. She was a member of the victorious United States team in seven Federation Cups and nine Wightman Cups.
King is an advocate of gender equality and has long been a pioneer for equality and social justice. In 1973, at the age of 29, she famously won the "Battle of the Sexes" tennis match against the 55-year-old Bobby Riggs. King was also the founder of the Women's Tennis Association and the Women's Sports Foundation. She was instrumental in persuading cigarette brand Virginia Slims to sponsor women's tennis in the 1970s and went on to serve on the board of their parent company Philip Morris in the 2000s.
King was inducted into the International Tennis Hall of Fame in 1987. The Fed Cup Award of Excellence was bestowed on her in 2010. In 1972, she was the joint winner, with John Wooden, of the Sports Illustrated Sportsman of the Year award and was one of the Time Persons of the Year in 1975.