Toronto EMS was called to the intersection of Redpath and Broadway Avenues — in the area of Mt. Pleasant Road and Eglinton Avenue East — just after 9:20 a.m. Friday.
She is in serious condition with leg injuries that are believed to be non life-threatening.
Witness Fred Steiss told CBC News the police car appeared to be making a left turn when the woman was struck as she walked through the intersection with her dog.
"He was making a turn and it looked like he just didn't see her," Steiss told CBC News.
He said the collision sent the woman over the top of the vehicle. Witnesses said the woman who was struck was conscious when paramedics arrived.
Police confirmed to CBC News that the woman was hit by a police car but said they could not comment until they learn more about the incident.