The motorway had to be closed near Barnsley after a member of public reported the item on an old railway bridge that carries the Trans Pennine Trail over the M1.
Drivers including Sunderland fans heading to an away match against Sheffield Wednesday were caught up in the tailbacks while an army bomb disposal team investigated.
However the package turned out to be empty, though it has been sent for further analysis.
South Yorkshire Police said: "We were called at about 1.10pm on Monday by a member of the public to report a suspicious-looking package on an old railway bridge that carries the Trans Pennine Trail over the M1 just off Gilroyd Lane in Barnsley.
"Officers and specialist teams including an EOD disposal unit attended the scene and the M1 had to be closed in both directions between Junction 36 and Junction 37 while investigations determined what the package was.
"It was determined that the package was empty, and it is now being forensically examined to determine where it came from.
"The M1 was able to open up again in both directions by 8pm. We appreciate the disruption caused keeping the public safe while these investigations were carried out. We would like to thank everyone for their patience while that work took place."