The 2026 Markham 125 was the eleventh stock car race of the 2026 NASCAR Canada Series and was the inaugural running of the race. The race was held on Saturday, August 15, 2026, at Markham Street Circuit, a 2.187 mi street circuit in Markham, Ontario, Canada. The race went beyond the scheduled 35 lap distance, going into overtime. Polesitter Marc-Antoine Camirand, who had led the entire race, held off Andrew Ranger and L. P. Dumoulin to score the win, tying the single season win record with his seventh of the season. Ranger finished second and Dumoulin rounded out the podium in third.