Updated July 2017

All these links are live but I make no claims about the quantity or quality of their listings. Anyway, nothing beats walking the neighbourhoods you like and looking for À LOUER signs.

padmapper and rentalguru both let you specify your parameters then display apartment listing markers from multiple sources onto Google maps

appartalouer.com
Logis Québec
Concordia student union off-campus job and housing bank
craigslist
Journal de Montréal classifieds
kijiji
Les petites annonces classées lespac.com
locanto
louer.com
McGill housing classifieds
Montréal en ligne
More Montreal / Tout Montréal
Top Annonces
UQÀM listings