Lorry driver Zdzislaw Piorko, 53, from Maidstone in Kent, died at the scene along with coach passenger Delia Walker, 63, from Pontefract, West Yorkshire, following the accident early Saturday morning, Essex Police said.
A statement from the East of England Ambulance Service said 50 passengers were on board the coach when the accident happened on the southbound carriageway of the M11 between Saffron Walden and Stansted.
Karl Edwards, of the East of England Ambulance Service, said: "We worked as safely and as quickly as possible to ensure patients were assessed and treated in a timely manner.
"Sadly, despite all efforts, two people were declared deceased at the scene - our thoughts are with their families at this time.
"There were 49 other patients, whose injuries included neck and back pain, and shock, and other minor injuries consistent with this kind of collision. Patients were then taken to hospitals in Cambridge, Harlow and Chelmsford."
Three people injured in the crash remained in hospital, the service said.
The motorway was temporarily closed in both directions between between junction 8, the turn-off for Stansted Airport, and junction 9 at Great Chesterford. It has since reopened on both southbound and northbound carriageways.
Simon Posner, of the trade association the Confederation of Passenger Transport UK (CPT), said the coach had been carrying passengers from the West Yorkshire area who were heading to Folkestone, Kent, en route to Belgium for a shopping trip.
"It was not one group of passengers, lots of people will have booked a day trip from around West Yorkshire, and the pick-up points would have been in Castleford and Wakefield," he said. "The great majority of passengers will have been from the West Yorkshire area."