McCormack left Elland Road for Fulham three years ago, but according to the Daily Mail the Championship club are interested in adding him to their squad to boost their promotion bid.
The 30-year-old spent last season with Aston Villa, but he struggled to recapture his previous form and spent the second half of the campaign on loan to Nottingham Forest.
Sunderland have also been linked with a move for McCormack, but Leeds are on the hunt for another striker after allowing Marcus Antonsson to spend the season at Blackburn Rovers and could be a more likely option.