"I'm so excited to compete in my first Olympics!!!" she said on Instagram earlier this month. "See you soon Tokyo."
But, taking to social media on Sunday, the 17-year-old tennis star posted a statement announcing her withdrawal from the upcoming games and shared her disappointment at being unable to play.
"I am so disappointed to share the news that I have tested positive for COVID and won't be able to play in the Olympic Games,' Gauff said.
"It has always been a dream of mine to represent the USA at the Olympics, and I hope there will be many more chances for me to make this come true in the future," she went on.