The boyband will release 'Proud' as this year's official Sport Relief charity single on March 19.
The accompanying music video was filmed at Wembley Stadium and the newly-released behind-the-scenes footage hears the group's thoughts on appearing at the legendary sporting venue.
Aston Merrygold explained: "I didn't quite think I'd be walking out to Wembley Stadium doing a music video. I thought I'd be out here in a World Cup final. But this is just as good, I'm not going to lie."
The video also stars Olympic athletes Rebecca Adlington, Phillips Idowu and Louis Smith.
Speaking about her feature in the video, Adlington added: "It's absolutely amazing. I totally rescheduled my day just to be here, it's such an honour being in the video."
JLS will perform 'Proud' on the Sport Relief night of entertainment, which starts on Friday, March 23 at 7pm on BBC One.
They will also be performing a special one-off matinee concert for Sport Relief at The O2 on March 24 and will be joined by Olly Murs and Rizzle Kicks.
> JLS premiere official 'Proud' music video - watch
> JLS release new single 'Proud' a cappella for fans - listen
Watch behind-the-scenes footage of JLS's 'Proud' music video below: