Billie Jean King (née Moffitt; born November 22, 1943) 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. She has also received the Presidential Medal of Freedom and the Sunday Times Sportswoman of the Year lifetime achievement award. She was inducted into the National Women's Hall of Fame in 1990, and in 2006, the USTA National Tennis Center in New York City was renamed the USTA Billie Jean King National Tennis Center. In 2018, she won the BBC Sports Personality of the Year Lifetime Achievement Award. In 2020, the Federation Cup was renamed the Billie Jean King Cup in her honor. In 2022, she was awarded the French Legion of Honour, and in 2024, she received a Congressional Gold Medal.
Billie Jean Moffitt was born in Long Beach, California, into a Methodist family, the daughter of Betty (née Jerman), a housewife, and Bill Moffitt, a firefighter. Her family was athletic; her mother excelled at swimming, and her father played basketball and baseball and ran track. Her younger brother, Randy Moffitt, became a Major League Baseball pitcher, pitching for 12 years in the major leagues for the San Francisco Giants, Houston Astros, and Toronto Blue Jays. She also excelled at baseball and softball as a child, playing shortstop at 10 years old on a team with girls 4–5 years older than she. The team went on to win the Long Beach softball championship.
She switched from softball to tennis at the age of 11, because her parents suggested she should find a more 'ladylike' sport. She saved her own money, $8 ($92.40 in 2024), to buy her first racket. She went with a school friend to take her first tennis lesson on the many free public courts in Long Beach, taking advantage of the free lessons offered by professional Clyde Walker, who worked for the City of Long Beach. One of the city's tennis facilities has subsequently been named the Billie Jean Moffitt King Tennis Center. As a kid playing in her first tennis tournaments, she was often hindered by her aggressive playing style. One of King's first conflicts with the tennis establishments and status-quo came in her youth, when she was forbidden from being in a group picture at a tournament because she was wearing tennis shorts (sewn by her mother) instead of the usual white tennis dress.
King's family in Long Beach attended the Church of the Brethren, where the minister was former athlete and two-time Olympic pole-vaulting champion Bob Richards. One day, when King was 13 or 14, Richards asked her, "What are you going to do with your life?" She said: "Reverend, I'm going to be the best tennis player in the world."
King attended Long Beach Polytechnic High School. After graduating in 1961, she attended Los Angeles State College, now California State University, Los Angeles (Cal State LA). She left the school in 1964 to focus on tennis, but returned in 2025, completing her degree in history in May 2026 at age 82. While attending Cal State, she met Larry King in a library in 1963. The pair became engaged while still in school when Billie Jean was 20 and Larry 19 years old and married on September 17, 1965, in Long Beach.
King's French Open win in 1972 made her only the fifth woman in tennis history to win the singles titles at all four Grand Slam events, a "career Grand Slam". She also won a career Grand Slam in mixed doubles. In women's doubles, only the Australian Open eluded her.
King won a record 20 career titles at Wimbledon – six in singles, 10 in women's doubles, and four in mixed doubles.
King played 51 Grand Slam singles events from 1959 through 1983, reaching at least the semi-finals in 27 and at least the quarterfinals in 40 of her attempts. King was the runner-up in six Grand Slam singles events. An indicator of her mental toughness in Grand Slam singles tournaments was her 11–2 career record in deuce third sets, i.e., third sets that were tied 5–5 before being resolved.
King won 129 singles titles, 78 of which were WTA titles, and her career prize money totaled US$1,966,487.
In Federation Cup finals, she was on the winning United States team seven times, in 1963, 1966, 1967, and 1976 through 1979. Her career win–loss record was 52–4. She won the last 30 matches she played, including 15 straight wins in both singles and doubles. In Wightman Cup competition, her career win–loss record was 22–4, winning her last nine matches (six in singles and three in doubles). The United States won the cup in ten of the 11 years in which she participated. In singles, King was 6–1 against Ann Haydon-Jones, 4–0 against Virginia Wade, and 1–1 against Christine Truman Janes.
As Billie Jean King began competing in 1959, she began working with new coaches including Frank Brennan and Alice Marble, who had won 18 Grand Slam titles as a player herself. She made her Grand Slam debut at the 1959 U.S. Championships when she was 15. She lost in the first round. She began playing at local, regional, and international tennis championships. Sports Illustrated already claimed her as "one of the most promising youngsters on the West Coast." She won her first tournament the next year in Philadelphia at the 1960 Philadelphia and District Grass Court Championships. At her second attempt at the U.S. Championships, King made it to the third round, losing to Bernice Carr Vukovich of South Africa. Also in 1960, she reached the final of the National Girls' 18 and Under Championships, losing to Karen Hantze Susman. Her national tennis ranking improved from number 19 in 1959 to number 4 in 1960. Despite the success, Marble terminated her professional relationship with King, for reasons stemming from King's ambition.
King first gained international recognition in 1961 when the Long Beach Tennis Patrons, the Century Club, and Harold Guiver raised $2,000 to send her to Wimbledon. There, she won the women's doubles title in her first attempt while partnering Karen Hantze. King was 17 and Hantze was 18, making them the youngest team to win the Wimbledon Doubles Title. King had less luck that year in the 1961 Wimbledon women's singles, losing to fifth-seeded Yola Ramírez in a two-day match on Centre Court. Despite these performances, she could not get a sports scholarship when later that year she attended Los Angeles State (now California State). For the 1962 singles tournament at Wimbledon, King upset Margaret Court, the World No. 1 and top seed, in a second round match by attacking Court's forehand This was the first time in Wimbledon history that the women's top seed had lost her first match. That same year, King and Hantze repeated their doubles victory at Wimbledon. In 1963, King again faced Margaret Court at Wimbledon. This time they met in the final, and Court prevailed.
In 1964, King won four relatively minor titles but lost to Margaret Court in the Wimbledon semi-finals. She defeated Ann Haydon-Jones at both the Wightman Cup and Fed Cup but lost to Court in the final of the Federation Cup. At the U.S. Championships, fifth-seeded Nancy Richey upset third-seeded King in the quarterfinals. Late in the year, King decided to make a full-time commitment to tennis. While a history major at Los Angeles State College, King made the decision to play full-time when businessman Robert Mitchell offered to pay her way to Australia so that she could train under the great Australian coach Mervyn Rose. While in Australia, King played three tournaments that year and lost in the quarterfinals of the Queensland Grass Court Championships, the final of the New South Wales Championships (to Court), and the third round of the Victorian Championships.