Taylor has made a special video of the track, including her discussing the project with clips from the film One Chance.
The Weinstein Company had screened the film for Swift, along with her family, at the suggestion of executive producer Simon Cowell. Taylor had a very strong emotional response to the film, which inspired her to write Sweeter Than Fiction.
Taylor Swift said: 'I'm flattered to have been asked to be part of One Chance. This is truly a touching and inspirational story.'
One Chance producer, Harvey Weinstein, on Taylor's involvement: 'After Taylor screened One Chance, she went right into the studio and sent us what she'd recorded. We instantly felt that she'd really connected the essence of its message, which is about never giving up on one's dreams. We're beyond thrilled to have a musician of her stature supporting the film.'