London Broncos will change their name to Harlequins Rugby League next season and move to the Stoop in a link-up with the Harlequins rugby union club.
As part of the "long-term partnership", the league side will sport the famous Harlequins colours and jester logo.
And the Stoop Memorial Ground will be renamed the Twickenham Stoop.
"We have the opportunity in the coming years to build Harlequins into a powerhouse in both codes," said Quins chief executive Mark Evans.
Although the Broncos will take on the Harlequins name, they have stressed that the deal is not a merger or takeover and that the clubs remain separate entities.
They will keep the Broncos name and colours and continue to play at Brentford Football Club's Griffin Park for the rest of the Super League season.
Broncos chairman Ian Lenagan said: "While this is not a merger or takeover in either direction it does represent the most exciting coming together of rugby union and rugby league ever.
"It represents coming together under the most famous rugby brand in the world and with the most capable boards of directors on the rugby union side and the rugby league.
"We feel sure it is a very, very strong future for rugby league in the capital."
The partnership will involve the two teams sharing Quins' Roehampton training facilities and pooling player development, administrative and commercial resources.
"Everyone at NEC Harlequins is very excited by this partnership and determined that this venture will be a successful one," added Evans, whose side were relegated from the Zurich Premiership last season.
"Although we're steeped in tradition, Quins is also a club with some very progressive and dynamic ideas.
"This partnership is another proactive step in the evolution of the Harlequin brand and club."
The Broncos' move is the ninth in the 25-year history of rugby league in London.
The Broncos reached the 1999 Challenge Cup final during a previous stay at The Stoop from 1997-1999.
But they failed to build on the success and since 2002 they have played five miles down the road at Griffin Park.
They have played under the name the Broncos since 1994, having previously been known as the Crusaders.
The club was re-formed four months ago after going into liquidation with debts estimated at £3m.
Sports Cafe boss Lenagan took over as chairman last week and assumed joint control with former owner David Hughes.