A 29-year-old man was struck by an OC Transpo bus at the corner of Laurier Avenue East and Waller Street, and his leg was pinned underneath a wheel.
It happened at about 2:52 p.m. Wednesday, police said.
The man was conscious when police, paramedics and firefighters arrived at the intersection.
Firefighters said crews were able to get the man out from under the bus without lifting it. He was taken to The Ottawa Hospital's Civic campus trauma unit in serious but stable condition.