One lane has been closed on both carriageways of the motorway while police and Highways England staff deal with the crash, between junctions 22 and 23 at Scammonden.
The Yorkshire Ambulance Service has also been sent to the scene.
Drivers have been told to expect delays of around 30 minutes, with four miles of the motorway said to be affected by traffic congestion.
In a tweet shortly after 2pm, Highways England said: “Recovery is now on scene. Our crews are working to get the lane closures removed as soon as it is safe to do so.”