RFL chief Richard Lewis has insisted fans will not lose out by the switch of the Challenge Cup final to Twickenham.
Twickenham hosted the Challenge Cup final in 2001
The 26 August final was moved because Wembley will not be ready in time.
"It's disappointing not to be playing this prestigious game at Wembley but the Challenge Cup final is all about the event," said Lewis.
"Fans will still experience the unique atmosphere and spectacle that's made the Challenge Cup final a key part of the national sporting calendar."
Twickenham is, of course, the home of English rugby union, but the stadium has staged several major rugby league games in the past including the opening match of the 2000 World Cup and the 2001 Challenge Cup final.
The announcement represents good financial news for the Rugby Football Union, coming soon after its admission that England's poor showing in the Six Nations had cost it about £1m.
RFU business operations director Paul Vaughan said: "We're delighted that we can help out and provide Twickenham Stadium for such a prestigious occasion.
"We've worked well with the RFL in the past and we look forward to doing so again."
The stadium will also benefit by hosting two sell-out concerts by rock band The Rolling Stones after they were switched from Wembley.
Wembley has been the traditional home of the Challenge Cup final, staging every final from 1929 until 1999.
Since then, it has been played at Twickenham, Murrayfield and the Millennium Stadium.
"Twickenham is a world-class facility in which to showcase this premier rugby league match," added Lewis.
Hull coach John Kear said the move was a "huge disappointment" and suggested the RFL should look at a more permanent role for Cardiff's Millennium Stadium.
Kear, whose side won the trophy last year in Cardiff, said: "The RFL have nothing to be ashamed of. They have already sold 35,000 tickets and it is as disappointing for them as it is for everyone else.
NO LONGER AT WEMBLEY
Gigs: Bon Jovi, Take That, Rolling Stones, Robbie Williams
Football: 2006 FA Cup final, Community Shield, two England games
Rugby league: Challenge Cup final
"I have been to Cardiff as a spectator, as a commentator and as a participant and it is a wonderful venue.
"I believe that Cardiff has become the new spiritual home of rugby league and at least one showpiece event should be there every season.
"It was a special weekend for the fans as they took over the city and made it like a carnival. You can't do that in London as everything gets swallowed up by everything else."
The RFL has said that all of the 35,000 tickets sold for the event will be transferable to Twickenham.
"Transferred tickets will be posted to supporters well in advance of the event," said RFL marketing director Simon Malcolm.
"We will also be loading information regarding travel and parking onto the RFL website.
"The final remains firmly in place in the hearts of rugby league supporters who, I have no doubt, will celebrate the culmination of this great knock-out competition in style at Twickenham in August."