The accident happened at around noon when the bus of Noida Metro Rail Corporation (NMRC) hit the tractor, coming from opposite direction near the underpass, they said.
The driver of the tractor, Rahul died on the spot while three others -- Sonu, Vipin and Raju got injured.
Those injured were admitted to a private hospital, they said, adding after the accident, traffic jam was witnessed on the Expressway.
It ended after few hours when the bus and tractor were removed from the accident site, they added.