Chantal Demers was last seen in the Lac-St-Charles area in the north of the city.
She hasn't been seen since May 3.
Demers' partner, 47-year-old Victor Poirier was arrested on Friday and charged with assault causing bodily harm for offences allegedly committed in April.
Demers is 4-foot-11, weighs 95 pounds and has brown eyes and brown hair.
Quebec City police are asking anyone with information to call 418-641-AGIR.