Highways England reported the crash at 12pm.
It happened on the northbound carriageway between junction 39 and junction 40, near south Elmsall.
Highways officers and West Yorkshire Police are at the scene working to clear the vehicles from the carriageway.
One driver, Andy, said he was stationary on the northbound carriageway for about 20 minutes as emergency services attended the crash.
There are delays of about 30 minutes on the approach to the scene, building back to junction 38 at the Redhouse Interchange.
Highways England has warned drivers to allow extra time for their journey.