Gibson, 76, had been seriously ill for several years. She died at a hospital in East Orange, N.J., after two days in the intensive care ward.
Gibson was the first black player on the LPGA Tour. She became a household name on the tennis courts, winning Wimbledon and the U.S. tennis Open in 1957 and 1958 - also the first black to do so.
Gibson was born Aug. 25, 1927, in Silver, S.C., and lived in East Orange for most of the last 30 years. The Althea Gibson Foundation, based in Newark, was created to help urban youth develop their skills in tennis and golf.
Gibson retired from the tennis soon after her 1958 Wimbledon and U.S. Open titles because there was no prize money and few lucrative endorsements. She turned pro and, together with Karol Fageros played before Harlem Globetrotter games. It wasn't until 1968, the start of the Open era, that the major tennis tournaments paid pro players.
She took up golf in 1962, when a friend took her to Inglewood Country Club in New Jersey. By now she was 34 years old, and at Inglewood she was offered the facilities of the club and took lessons from the pro.
The challenge of being accurate, of hitting a still ball and making it do what you want, opened another avenue of athletics for me, she told British writer Liz Kahn.
I was not ready to hang up my sports equipment; I still felt strong, agile, and my mind was clear on what I wanted to do. I had never seen a womens professional golf tournament. I didnt think I knew any of the players, but there was a tour in existence for women, there was an organization for women, and I wanted to be a professional golfer.
I spent every day practicing, as well as playing 18 or 36 holes. I turned professional in 1963, when I was 36 years old.
She became the first black player on the circuit, during an era when segregation was still quite strong throughout the country. She was refused entry at a California club when she tried to take lessons from Betty Hicks. She was refused admittance to many restaurants and hotels. It was just such an occasion when she was denied a room in Columbus, Ohio, when Marlene Hagge happened by and was horrified by what she heard. Hagge told Gibson to come with her, and the two became friends and frequent roommates.
Gibson, however did not become as outstanding a player in golf as she had become in tennis. She played in six events her first year, 1963, but her scoring average was 77.73, too high to keep her card. In 1964 she gained it after playing in four tournaments. Her best year was 1967, when she won $5,567 in 25 events. She was 23rd on the LPGA money list that year and finished a career-high third.
She continued to play in golf tournaments until 1977, when she was 50 years old. She retired and devoted her life to the foundation.
Gibson won her first tennis tournament at 15 after spending much of her early childhood in Harlem, becoming the New York State black girls' singles tennis champion. Boxer Sugar Ray Robinson helped pay for her travels.
She spent her high school years in Wilmington, N.C., then attended Florida A&M on a tennis and basketball scholarship. In 1950, she was the first black to play in the National Grass Court Tennis Championships, the precursor of today's U.S. Open, coming within a point of beating Wimbledon champion Louise Brough.
She broke the racial barrier at Wimbledon the following year.
'She was a great champion and great person. We had a good relationship - she was always there for me even when I was a nobody,' Martina Navratilova said Sunday in Leipzig, Germany, where she won her 172nd career doubles title.
'Her life was very difficult, but she broke down a lot of barriers and doors and made it easier for a lot of us.'
Gibson was The Associated Press' Female Athlete of the Year in 1957 and 1958. Following her 1957 Wimbledon victory, she was given a ticker-tape parade in New York City and an official welcome at City Hall.
Gibson was married twice; husbands William Darben and Sidney Llewellyn are deceased.