The 24-year-old man died at the scene of the early morning collision, which happened outside the New Victoria Hospital, in the south side of Glasgow yesterday.
The man, who was behind the wheel of a dark grey Hyundai coupe, appeared to steer the car across the carriageway before hitting the front of the double decker.
The First bus was waiting at traffic lights in Govan's Grange Road, near to the junction with Langside Road.
Passengers watched in horror as the car smashed into the bus at around 6.40am yesterday.
Emergency services rushed to the scene when they were alerted, however they were unable to save the man.
Police Scotland said relatives had been made aware and a report would be submitted to the Procurator Fiscal.
A police spokeswoman said the 27-year-old driver of the bus was uninjured but was "extremely shaken". He was taken to the New Victoria Hospital as a precaution. No passengers were injured.