The university's security service has issued an alert after receiving five reports of a man entering bathrooms and showers in the buildings or looking at partially-clothed women through unlocked doors.
There's concern that the suspect is becoming more brazen because, in the latest incident, a university official says the man climbed into bed with one of his victims.
The suspect flees when spotted and RCMP are still trying to compile a good description.
Patrols of the area have been stepped up and the University has bolstered its campus security by hiring a private firm to monitor the Vanier Place and Totem Park dormitories.
Several sexual assaults on the same campus in 2013 and 2014 remain unsolved but investigators say this case does not appear connected.