The 51-year-old, who won the Wimbledon singles title a record nine times, said she was maintaining dual nationality and keeping her American passport. But her announcement, at a Tokyo press conference, raised questions over whether she planned to leave the US after a series of controversial attacks on President Bush and the Republican Party.
Born in Prague, Navratilova defected to the United States in 1975 aged 18, angering communist authorities who stripped her of her nationality. She was granted a green card within a month and US citizenship six years later. She became known for her unstinting opposition to communism.
Navratilova said last year that while she was once ashamed about Czechoslovakia, she was now ashamed of the United States under Mr Bush. “The thing is that we elected Bush. That is worse. Against that, nobody chose a communist government in Czechoslovakia," she told the Czech daily Lidove Noviny.
In 2002 she told a German newspaper: “The most absurd part of my escape from the unjust system is that I have exchanged one system that suppresses free opinion for another. The Republicans in the US manipulate public opinion and sweep controversial issues under the table.
It"s depressing. Decisions in America are based solely on the question of how much money will come out of it and not on the questions of how much health, morals or environment suffer as a result." She was confronted with her comments in July 2002 by Connie Chung, then a CNN talk show host, who told the tennis star that when she read them, “I wanted to say, go back to Czechoslovakia. You know, if you don"t like it here, this is a country that gave you so much, gave you the freedom to do what you want".
Navratilova, the winner of 59 Grand Slam titles, came out publicly in 1981 about her lesbianism, soon after being granted US citizenship. A long-term relationship with Judy Nelson, a former Texan beauty queen, ended in 1991, beginning a bitter legal battle.
Navratilova retired in 1994 but returned to play doubles in 2000, winning several tournaments. She hung up her racket in December 2006 after winning in mixed doubles at the US Open. She plans to open an academy in the Czech Republic.