The much-travelled striker spent the second half of the 2012/13 campaign on loan from Watford at Oldham Athletic.
He is now 34 years of age, but has shown over the course of his career that he can be a useful asset to any Football League side.
A former Scotland international, Iwelumo has made well over 500 career appearances.
It could be that he will take on another new challenge next season at Glanford Park.
Scunthorpe are looking to bolster their ranks after being relegated out of League One and feel an experienced frontman would aid their cause.
Iwelumo will become a free agent in the summer as his contract with Watford is due to expire.