The 37-year-old confirmed her sexuality in a video on Tik Tok and Instagram.
On the video , played to the rapper Kill Whitey track Gay, she pointed to captions asking whether she was into women and whether she was a lesbian, before lip synching to the chorus saying “B****, I’m, I can’t even think straight.”
She later added on Twitter: “I’m lesbian not bi, just saying.”
Talking to Vogue she said: “No one’s ever really cared about me being bisexual and I only came out because I had always been out, it’s just the general public didn’t know.”
Adams won the gold medal for women’s boxing at the 2012 Olympics, the first openly LGBT person to do so.
Adams, who retired from the sport last year, will shortly appear Strictly Come Dancing where she will dance in the show’s first ever same-sex partnering.