Saint-Étienne-des-Grès is a parish municipality in the Mauricie region of the province of Quebec in Canada.

Autoroute 55 is an important north–south Autoroute and the only one running in that direction in central Quebec. It is the longest north-south Autoroute, beginning as the continuation of I-91 at the Canada–United States border near Stanstead and continuing to Shawinigan, where it downgrades to Route 155. The total length of A-55 is currently 247 km (153.5 mi) long, including concurrencies with Autoroute 10, Autoroute 20 and Autoroute 40.