The victims, who were in their early twenties, complained to police on Oct. 20 and Oct. 27 after being groped while on Clarence Street in the late evening to early morning hours, said an Ottawa police news release Friday.
In both cases, the women had flagged down a taxi rather than ordering one by phone.
They described the suspect as being an English-speaking man of Middle Eastern descent in his mid 30s, police said. He had a medium build, short black hair, and was wearing a Bluetooth wireless phone headset on his ear.
One of the victims identified the taxi he was driving as being from Blueline Taxi.
Police are seeking information from the public and are also advising taxi customers to take note of the identification number inside each vehicle.
A taxi driver allegedly sexually assaulted a customer picked up in the same area in June. A 34-year-old driver was charged with sexual assault about a month later.