The Red Bull driver clocked a best of 1min 13.784sec around the Gilles-Villeneuve circuit, with Briton Lewis Hamilton in second place and Spaniard Fernando Alonso of Spain coming in third.
The German world champion was 0.303 seconds quicker than Hamilton — the biggest margin between the two quickest cars all weekend.
Sahara Force India’s Paul di Resta clinched the eighth spot while McLaren’s Jenson Button finished 10th.
Canadian GP starting grid
8) Di Resta