In an essay for Vanity Fair, she announced her decision, saying she's "ready to scale another mountain".
"In giving my life to tennis, tennis gave me a life," Sharapova wrote. In the essay, she asks: "How do you leave behind the only life you've ever known?
Born in Russia, Sharapova burst onto the international scene at 17 years old when she beat Serena Williams in an upset at the 2004 Wimbledon final.
One year later, Sharapova reached No. 1. In total, she spent 21 weeks as the World Tennis Association's world No.1.
Sharapova's career was derailed after a doping ban in 2016 that barred her from playing for 15 months. She has also long dealt with problems in her right shoulder, forcing her to undergo multiple surgeries, the most recent in 2019. Today she is ranked 373 in the World Tennis Association singles rankings.