Read more on the launch of the band's first film here.
Thousands of One Direction fans are expected at tonight's premiere of the boyband's first film.
It is called One Direction: This Is Us, and it follows their life on the road during their rise to worldwide fame.
Leicester Square is "full to capacity" thanks to the One Direction film premiere, according to this Transport for London sign.
One Direction's feature film This Is Us has great odds to become the UK's highest grossing film ever, according to bookmakers Ladbrokes.
As the premiere launches tonight, bookies are speculating at its potential success and make it a 5/1 chance to win a BAFTA award for Outstanding Debut in 2014.
The film chalked up at 4/1 to be the country's highest-grossing film ever, beating the record set by Skyfall in 2012.
Jessica Bridge of Ladbrokes said: "One way or another this film is going to break records and win awards. The 1D phenomenon is showing no signs of slowing down and the odds suggest they could be adding a BAFTA to their tour bus mantelpiece."
One Direction boys - Louis Tomlinson, Niall Horan, Zayn Malik, Liam Payne and Harry Styles - held a press conference in London yesterday, where Liam said the film had been 'nerve-wracking' to make.
But Liam says there could be a follow-up if this film is a hit:
"It's so nerve-wracking making the film. When we sit in the premiere and everybody is actually watching it on the big screen it is going to be amazing but I don't know, maybe we'll see how this one goes, see if people like it."
One Direction told ITV News that although being compared to The Beatles was "very flattering" it was "not necessarily something we agree with".
The hysteria surrounding Harry, Niall, Zayn, Louis and Liam was compared to Beatlemania in the 1960s by This Is Us director Morgan Spurlock.
However, the boys dismissed the claims, saying the Liverpudlian foursome were "in a league of their own" and "much cooler than us".
The most successful British band to come from the X Factor, One Direction, have launched their first feature film.
The film is called One Direction: This Is Us and follows the band for six months, including on their current world tour.
One Direction were left stumped when a journalist asked them what a fan should say to their partner when trying to convince them to watch their new film This Is Us.
After plenty of thought from Harry Styles, director Morgan Spurlock stepped in and said "if he really loves you, he will go to the film".
One Direction members Niall Horan, Louis Tomlinson and Liam Payne are in London today promoting their new film This Is Us. The 1D artists said they "can't wait" for it to be released.
Can't believe it's #TwoYearsOfWhatMakesYouBeautiful and this week we premiere our movie This Is Us thank you!
Great to be back with the lads today! Can't wait for the movie :) x
One Direction's Zayn Malik said the band are not thinking about pursuing an acting career despite the release of their first feature film.
The documentary, directed by Supersize Me creator Morgan Spurlock, follows the five boys, Zayn, Niall, Louis, Harry and Liam, as they travel around the world.