An MTA bus driver was punched in the face in an unprovoked Queens attack over the weekend, cops said. 

The 42-year-old driver was operating a Q18 bus at 27th Avenue and Fourth Street in Astoria around 5 p.m. Sunday when a passenger slugged him for no apparent reason, police said. 

The attacker ran off the bus after the incident, and police did not have a description of the menace Monday morning. 

No arrests have been made.

The driver was taken to Mount Sinai Hospital with non-life-threatening injuries, and the bus was taken out of service, according to cops and the MTA.

“It is unconscionable that anyone would attack a bus operator who is simply doing his or her job,” MTA rep Michael Cortez said in a statement. “The MTA is cooperating fully with this investigation to ensure the perpetrator can be brought to justice.”

The incident comes weeks after Jonathan Frias, 28, who is homeless, allegedly bashed a 46-year-old female city subway cleaner with a metal pipe at a Lower Manhattan station, cops said. 

Last month, a Harlem bus passenger also flipped out on a 52-year-old male driver — spitting on him, slashing him on the arm and threatening to “go get my gun,” cops said.