Sheeran told Australian radio station Nova that he would be playing at the event and cleared up rumours he'd be collaborating with The Who.
"A lot of people think that I'm doing a song with The Who but I'm not - I'm doing a song with Pink Floyd. I'm doing 'Wish You Were Here'," he said.
However, NME reports that Pink Floyd have released a statement saying: "In response to press speculation, Pink Floyd state that the band is NOT performing at the closing ceremony of the London 2012 Olympic Games."
Sheeran had said that the performance wouldn't include all surviving members of the band but claimed drummer Nick Mason would be involved.
One Direction, Jessie J and Sir Elton John have all been linked to the closing ceremony, which will celebrate the best of British music.
Photo gallery: London 2012 Olympics: