My favorite place to pick up certified gluten-free macarons in Montreal is Boutique Point G on Mont-Royal E. Most macarons are gluten-free as they are made with ground almonds, but there are some places in Montreal where certain flavors are not gf or they have come in contact with gluten. Always make sure when it comes to macarons.
All the macarons at Point G are gluten-free and so are most of the products sold in the store. They are great for any occasion and also make a really nice gift.
They have a cute store on Mont Royal and their macarons are also sold at some bakeries across the city. My favourites are the Caramel Fleur de Sel, Poppy Flower and Lavender-Blueberry.
Boutique Point G- 1266 rue Mont-Royal est, Montreal, H2J 1Y3