The incident occurred around 3pm in the municipality of Oetwil am See, southeast of the city of Zurich.
A car driven by a 60-year-old woman struck the man, Zurich cantonal police said.
For reasons not immediately known the woman did not brake to slow down when she drove behind two vehicles that were stopped in front of a pedestrian crossing to let a person walk across the road, police said.
The woman’s car swerved and struck a lamppost before hitting the two stopped vehicles and striking the man seated at the bus stop.
The senior suffered severe leg injuries and had to be airlifted to hospital with life-threatening injuries by a Rega emergency rescue helicopter, cantonal police said.
The exact circumstances of the accident remain unclear, said police.
An investigation was launched into the case by the local prosecutor, Zurich cantonal police and officers from the Oetwil am See police force.