Philippe Steele Morin was being sought on charges of second-degree murder in the death of Tricia Boisvert.
He was arrested Monday afternoon in Buckingham, a sector of Gatineau.
The 36-year-old Boisvert was killed in her Montreal apartment in mid-January.
She was found six days later in a wooded area near Pontiac, a municipality in the Outaouais region in western Quebec.
Investigators were planning to question him at a detention facility on Monday.