Blackpool's Jake Daniels said his decision to come out as the UK's only openly gay active male professional footballer would allow him to be "free and confident".
The Championship club forward is the first professional in the UK men's game for more than 30 years to come out while still playing.
Speaking to Sky Sports, the 17-year-old said: "Now is the right time to do it.
"I feel like I am ready to tell people my story."
He added: "Since I've come out to my family, my club and my team-mates, that period of overthinking everything - and the stress it created - has gone. It was impacting my mental health. Now I am just confident and happy to be myself finally.
"I have been thinking for a long time about how I want to do it, when I want to do it. I know now is the time. I am ready to be myself, be free and be confident with it all."
Justin Fashanu was the last active men's professional footballer in the UK to come out during his playing career, featuring for clubs in England and Scotland after announcing in October 1990 that he was gay.
Adelaide United player Josh Cavallo is the only current openly gay top-flight male professional footballer in the world, having come out last October.
Daniels' announcement drew instant reaction, with UK Prime Minister Boris Johnson tweeting: "Thank you for your bravery Jake. It would have taken huge courage to come out and you will be an inspiration to many both on and off the pitch."
The football world also reacted swiftly, with the Premier League tweeting "the footballing world is with you", while Manchester United, Manchester City and Chelsea all said they were "proud" of Daniels.
Trevor Birch, chief executive of the EFL, said: "We hope that this moment helps take us forward to a time where LGBTQ+ representation at all levels of the men's professional game is the norm."
'I've been hiding who I am'
Daniels said he had known he was gay since the age of five or six and that his girlfriends in school were "a massive cover-up".
He said: "In school people even used to ask me: 'Are you sure you aren't gay?' And I would reply, 'no, I'm not'. I wasn't ready and it was a struggle but I just don't want to lie any more."
He says the fact he scored four goals in a youth fixture the day after telling his mother and sister showed the "massive relief" he was feeling.
"Of course I am aware that there will be a reaction to this and some of it will be homophobic, maybe in a stadium and on social media," Daniels added.
"It's an easy thing for people to target. The way I see it is that I am playing football and they are shouting stuff at me, but they are paying to watch me play football and I am living my life and making money from it. So shout what you want, it's not going to make a difference."
Daniels - who has been with Blackpool since the age of seven and now has a professional contract - made his first-team debut earlier in May and said his announcement came at the end of what he said has been a "fantastic" season for him.
"But off the pitch I've been hiding the real me and who I really am," he told Blackpool's website. "I've known my whole life that I'm gay, and I now feel that I'm ready to come out and be myself.
"It's a step into the unknown being one of the first footballers in this country to reveal my sexuality, but I've been inspired by Josh Cavallo, Matt Morton and athletes from other sports, like Tom Daley, to have the courage and determination to drive change."
Daniels said he had confided in youth-team players, who have supported and embraced his decision.
"I've hated lying my whole life and feeling the need to change to fit in," he added. "I want to be a role model myself by doing this.
"There are people out there in the same space as me that may not feel comfortable revealing their sexuality. I just want to tell them that you don't have to change who you are, or how you should be, just to fit in."
Before Daniels' announcement, Fashanu was the only male footballer to have come out as gay while playing professionally in the UK.
Speaking on behalf of the foundation set up in memory of her uncle, who killed himself in 1998, Amal Fashanu said there is still homophobia in football and called for it to be treated with "zero tolerance".
She added: "Jake's announcement will come as a huge comfort to the many footballers at all levels of the game, from grass roots to the professional leagues, still secretly living as gay and who still feel unable to come out."
There are a number of openly gay players in women's football, and several men's players have come out once their playing careers were over.
Former England international Casey Stoney said Daniels had shown "guts and courage".
She added: "Good for you for stepping out of the mould and for being authentically you. Wouldn't it be great if we got to a place where we didn't have to use the words 'guts and courage' to describe someone being comfortable being themselves."
- Justin Fashanu: 30 years since footballer came out (October 2020)
- Listen: Euro Leagues - Hitzlsperger's 'fantastic' journey since coming out (February 2021)
- Justin Fashanu: National Football Museum Hall of Fame induction 'deserved' (February 2021)
Former Aston Villa, Stuttgart, West Ham and Everton player Thomas Hitzlsperger - who came out as gay in 2013, shortly after retiring - congratulated Daniels.
"Well done Jake Daniels," he tweeted. "Have a wonderful career! Great to see the support of Blackpool FC and Stonewall UK to make this possible."
The Premier League partners with charity Stonewall's Rainbow Laces campaign, which is aimed at encouraging more acceptance of LGBT+ diversity.
Blackpool said it has worked closely with Stonewall to "support" Daniels and that the club "is incredibly proud that he has reached a stage where he is empowered to express himself both on-and-off the pitch".
The club added: "It is vital that we all promote an environment where people feel comfortable to be themselves, and that football leads the way in removing any form of discrimination and prejudice."
Stonewall director Liz Ward added: "Our Rainbow Laces campaign has taught us that, while there is still a way to go, attitudes towards LGBTQ+ people in sport are changing.
"We are moving towards a world where players can live openly as their true selves, both on and off pitch - and that is something we can all take pride in."