Ruth Volgl Cardoso (February 9, 1934 - February 11, 2000) was a Brazilian chess Woman International Master.
Her father was a Brazilian businessman who went to Germany to study engineering. There he met and married Ruth's mother, afterwards bringing her to Brazil where Ruth was born Salvador.
Shortly after Ruth was born, her parents' marriage ended, and Ruth and her mother went to Germany. World War II broke out and Ruth and her mother spent the period in East Germany. When the war ended, the Soviet Army took over East Germany. Ruth would have been trapped there, except that she had dinner with General Dwight D. Eisenhower, who saw to it that Ruth would be allowed to escape to Brazil.
Ruth Cardoso was, for many years, the strongest woman chess player in South America. She won the South American Women's Championship every time she competed (1966, 1969 and 1972). She won the Brazilian Chess Championship seven times. She played four times in the Women's Interzonal Championship. She played in five World Chess Olympiads, playing first board for the Brazilian team each time: in Skopje 1972, Medellín 1974, Buenos Aires 1976, La Valletta 1980, and Luzern 1982. Her trainer was grandmaster Pal Benko.
She played chess in the United States for thirty years, mostly in open Swiss tournaments. She was a popular chess personality, who was always able to see the bright side in the worst possible situations.
Ruth Cardoso was perhaps best known for playing in strong grandmaster tournaments in Spain and Italy in the 1970s. She played tournament games against grandmasters Ljubomir Ljubojević, Arturo Pomar, Jan Timman and Arthur Bisguier. She occasionally scored against the grandmasters, drawing with grandmasters Laszlo Barczay in Reggio Emilia 1970 and Miguel Quinteros in Malaga, Spain in 1971.
In addition to being a chess player, she was an artist and a woodcutter.
One confusing point which has often arisen is the similarity between her name and that of International Master Rodolfo Tan Cardoso of the Philippines. Rodolfo Cardoso became famous for playing a match against Bobby Fischer in 1957 and in the Interzonal in Portorož in 1958. As a result, when games played by R. Cardoso against grandmasters began being published in the 1970s, it was widely assumed that these were games played by Rodolfo Cardoso, whereas they were actually played by Ruth Cardoso. She is also sometimes confused with the wife of the former President of Brazil Fernando Henrique Cardoso, whose name is also Ruth Cardoso (Ruth Valença Correia Leite Cardoso).
Ruth Cardoso was married and divorced early in life and had no children. Her trainer, Benko, was also her long-time companion. She died of heart disease in her home city of Salvador.