This research was conducted in response to a report by a producer in southwestern Ontario of severe corn injury following an application that included multiple herbicides, an activator adjuvant, and a drift reduction agent. Eight field trials were conducted between 2024 and 2025 near Ridgetown, Ontario, Canada, to evaluate corn tolerance to mixtures of multiple active ingredients, an adjuvant, and drift retardent applied at two early postemergence growth stages (V2 to V3 and V3 to V4). Isoxaflutole applied alone or in combination with atrazine at either growth stage caused minimal visible corn injury at all time points, with ≤1% injury at 1 wk after application (WAA) and no injury at 2, 4, 6, and 8 WAA. Isoxaflutole + atrazine + glyphosate, applied at the V2–V3 or V3–V4 stage, caused 7% and 9% visible corn injury at 1 WAA and 3% and 5% at 2 WAA, respectively; however, visible corn injury was ≤1% at 4, 6, and 8 WAA. Isoxaflutole + atrazine + glyphosate + HiActivate, applied at the V2–V3 and V3–V4 stages, caused greater and more persistent visible corn injury, with 7% and 16% injury at 1 WAA and 5% and 10% injury at 2 WAA, respectively; visible corn injury declined to ≤5% at 4, 6, and 8 WAA. Isoxaflutole + atrazine + glyphosate + HiActivate + InterLock, applied at the V2–V3 and V3–V4 stages, caused 17% and 28% visible corn injury at 1 WAA and 11% and 17% at 2 WAA, respectively. Visible corn injury persisted with up to 8%, 7%, and 4% injury at 4, 6, and 8 WAA, respectively. There was no adverse effect on corn height, biomass, and grain yield with any of the treatments evaluated at either application timing. Results indicate that tank mixtures with multiple active ingredients can increase visible corn injury, but the injury was transient and did not affect yield.