The Premier League club are the first UK football team to collaborate with Stonewall and will work with the UK based charity to improve inclusion and equality in the sport.
As part of the partnership, United will become an official member of Team Pride, Stonewall's sporting initiative that counts telecoms firm O2, sportswear brand Adidas, broadcaster Sky Sports and the Premier League itself as existing supporters.
It builds on Man United’s existing relationship with Stonewall, which saw the team participate in the charity’s laces campaign. The initiative intended to show solidarity with LGBT campaigners through stunts such as players wearing rainbow-coloured laces, Rainbow Laces flags on display in stadium and holding meetings with LGBT fan groups.
"Manchester United always looks to be a leader in everything it does and we are proud to be the first sports club to sign up to Team Pride," said Richard Arnold, Manchester United's group managing director. "The club has an ongoing commitment to equality across all areas and with 659 million followers around the world, it is our responsibility to show support and recognition to everybody who loves this football club.
"We have built up a positive working relationship with Stonewall and it’s a great way for us to learn from each other and progress together as we strive for equality for all of our supporters."
Ruth Hunt, chief executive of Stonewall, added: "Manchester United’s support means we can reach millions of football fans both here and around the world, to encourage them to do their part in making all people feel welcome in sport.
"It’s crucial for organisations like Manchester United to show they not only welcome LGBT people, but are active in leading the change. At the moment, many LGBT people want to take part in sport, either as players or fans, but the behaviour of a minority can make them feel unsafe, unwelcome or unable to be themselves.
"There’s so much work left to do to ensure that all LGBT people feel able to participate in sport, and we hope to see other clubs take Manchester United’s lead and join the Rainbow Laces campaign to make this a reality."
The club will continue to support that project, in addition to hosting the 2017 Rainbow Laces Summit at its Old Trafford home stadium.