The 439 Express Pie-IX is a bus route in Montreal, Quebec, Canada. It is operated by the Société de transport de Montréal (STM). The route operates Monday to Friday during the morning and afternoon rush hour periods. It is a wheelchair accessible route. It serves the boroughs of Rosemont–La Petite-Patrie, Villeray–Saint-Michel–Parc-Extension and Montréal-Nord. It has 16 stops in the northbound direction and 24 stops in the southbound direction. It is also linked to Pie-IX Station of the Montreal Metro's green line. The fare is $3.25 cash (coins only) or an STM transit pass. The 439 serves an average of 7,000 daily passengers on an average weekday. An average 42,000 passengers use both the 139 and 439 combined during an average week day making it one of the busiest bus corridors in the city