A spokesman for West Yorkshire Police said they had a call at 8.40am today from a member of the public, who said they had seen a man fall from Scammonden Bridge, between junctions 22 and 23.
The man landed on a grass verge on the side of the carriageway.
Police officers attended along with paramedics, but the man was declared dead at the scene.
His death is not being treated as suspicious and his next of kin have been informed.
The incident caused major delays around the area while emergency services were at the scene.
A full closure of the motorway was put in place, with Highways England giving diversion routes for motorists.
The motorway was closed for around two hours and opened just before midday.