Canada and OL Reign midfielder Rebecca Quinn came out publicly as transgender in an Instagram post on Tuesday.
The 25-year-old player, who won Olympic bronze with the Canadian women's team in 2016 and played for Canada at the 2019 Women's World Cup, said the post was aimed at helping "queer folx" feel safe on social media.
"As I've lived as an openly trans person with the people I love most for many years, I did always wonder when I'd come out publicly," Quinn wrote.
"I wanted to be visible to queer folx who don't see people like them on their feed," Quinn added. "I know it saved my life years ago."
Quinn urged "cis folks" -- those who identify with their birth gender -- to be "better allies."
Quinn plays professionally for the Tacoma, Washington-based OL Reign of the National Women's Soccer League, and is currently on loan to Vittsjo GIK in Sweden.
Quinn is one of the most prominent North American team sports athletes to come out as transgender.
Triathlete Chris Mosier, who began his athletics career as a woman, competed for the US as a man in 2015.