Oritsé Williams revealed that he and fellow bandmates Aston Merrygold, Marvin Humes and JB Gill have written a track for the sporting event with producer Ali Tennant.
"I'm not supposed to say anything right now but we have written a song and are talking to people about it being the Olympic theme," Williams told The People.
"It is perfect, we were asked to do it. The song is uplifting, it's kind of along the lines of R Kelly's 'I Believe I Can Fly'. We wrote it with Ali, who is brilliant."
JLS will also feature on this year's X Factor charity single 'Wishing on a Star' alongside the current contestants and One Direction.
The band are due to perform on The X Factor results show tonight, singing new single 'Take A Chance On Me'.
Speaking of bandmate Merrygold, Williams added: "He can't speak at the moment, he has had to rest his voice. There has been a lot of colds going around so we haven't been out on the pull."
Watch JLS in their video for 'Take A Chance On Me' below: