Castonguay, société d'avocats is a law firm founded by Guillaume Castonguay in 2019 in Témiscouata-sur-le-Lac, Quebec, that has since opened offices in Rivière-du-Loup and Rimouski. The firm's lawyers practise in family law, civil and municipal law, criminal and penal law, administrative law, youth law, and family mediation, serving the Bas-Saint-Laurent region and the judicial district of Rimouski.

Good to know

A person using a wheelchairWheelchair accessibleA laptop showing a video callVirtual appointmentsA calendar with a checkmark beside a clockBy appointment

This firm’s lawyers at a glance

Called to the bar
2011–2019 · median 11 years in practice 2 of 4 lawyers
Law schools
Université de Sherbrooke, Université Laval 2 of 4 lawyers
Languages on the roster
French

Offices 4

421 Rue Denison O, Granby, QC J2G 8B6

22 Rue de l'Évêché E, Rimouski, QC G5L 8Y3

12 Rue de la Cour, Rivière-du-Loup, QC G5R 1J2

837 R. Commerciale N, Témiscouata-sur-le-Lac, QC G0L 1E0

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Listing compiled from the firm’s public website in August 2026. Verify licence status in the Barreau du Québec directory ↗