Belarusian Olympian Krystsina Tsimanouskaya touched down in Vienna on Wednesday, after a last minute change to the sprinter's scheduled destination.
She had been expected to fly to Warsaw, where the government has offered her and her husband humanitarian visas.
A Polish government source said the last-minute change was due to security concerns.
The apparent Cold War-style defection of an Olympic athlete has become one of the major news stories of the Games, and could further isolate Belarus following a crackdown against the opposition by President Alexander Lukashenko.
The Austrian Foreign Ministry confirmed she landed safely and was being taken care of.
Tsimanouskaya is expected to continue her journey to the Polish capital later on Wednesday.
The sprinter caused a diplomatic furore when she said coaches had ordered her to return home from Tokyo early because she had criticized them.
The Belarusian Olympic Committee said she was removed from the Games on doctors' advice about her 'emotional and psychological state'.
The International Olympic Committee has launched a disciplinary hearing into the case.
The affair has played out amid increased concern for the safety of Lukashenko's critics at home and in exile.