National Highways: Yorkshire said the carriageway has been 'fully blocked' at junction 23 due to a crash, which happened at around 1pm.
The motorway has been closed heading westbound between junction 24 for Outlane and junction 22 for Denshaw.
The agency said traffic officers were clearing debris and 'multiple vehicles' from the carriageway.
It tweeted: "#M62 westbound J24 #Outlane to J22 #Denshaw currently closed. The carriageway is fully blocked at J23 due to a traffic collision. #TrafficOfficers at scene currently clearing multiple vehicles and debris from the road. Delays are building. Please plan alternative route."
Images from motorway cameras also show traffic building up on the eastbound carriageway.
It is not yet known exactly how many vehicles have been involved, and if there are any injuries.