Fire and ambulance crews were called to Church Lane at 1.30am to reports of a man being knocked down by a car, which had been towing a caravan.
A spokesman from West Yorkshire Police said the man in his 20s, who has yet to be identified, had left a nearby house party with his girlfriend when the accident happened and he was trapped underneath the caravan.
Fire crews from Batley, Morley, Cleckheaton and Dewsbury helped release him, but he died at the scene.
Police closed to road to investigate, re-opening it at 5.20am.
They said it was unlikely anyone would be arrested over the incident.