The Joiners Arms, in Hackney Road, east London, shut in 2015.
Regal Homes, which wants to build nine flats on the site, incorporating a bar, has agreed to the planning condition, believed to be the first of its kind.
Tower Hamlets Council imposed the condition after the area lost 73% of its LGBT venues since 2006.
The Joiners Arms originally opened as an LGBT venue in 1997 and included fashion designer Alexander McQueen among its customers.
Regal Homes, which bought the site in 2014 - a year before the pub closed - has said it will give an LGBT operator first refusal on a 12-year lease for a new bar.
It added the redevelopment was expected to create 1,073 jobs.
The council has been working with Amy LamÃ©, the mayor of London's "Night Czar", on how to bring back a LGBT venue to Hackney Road.
In the application she says protecting LGBT venues is a "key part" of boosting London's "night-time economy".
"They contribute to London's economy, generate stronger and more resilient communities and are vital for many people's freedom of expression," she said.
"London has lost a quarter of its pubs and half of its nightclubs over the last 10 years."
She added a University College of London report showed the capital had lost 58% of its LGBT venues over the past decade, while Tower Hamlets had lost slightly more.
The czar said the report specifically cited the closure of The Joiner's Arms as one of several high-profile LGBT venues to shut in recent years.
The development is expected to be given the go ahead at a meeting of the council's planning committee on Wednesday.
John Biggs, mayor of Tower Hamlets, added: "Tower Hamlets Council is committed to celebrating our great diversity, which includes serving the needs of our LGBT+ community.
"I am delighted that as a council we are leading the way in using innovative ways to protect spaces such as the Joiners Arms site."
Council officials have insisted a redevelopment of a former gay pub in London still includes an LGBT venue for the plans to go ahead.