Accurately quantifying wildfire impacts on ozone air quality is challenging due to complex physical and chemical processes in wildfire smoke. Here we use measurements from the 2018 WE-CAN aircraft campaign to parameterize emissions of reactive nitrogen (NOy) from wildfires into PAN (37%), NO3- (27%), and NO (36%) in a global chemistry-climate model with 13 km horizontal resolution over the contiguous US. The NOy partitioning, compared with emitting all NOy as NO, reduces model ozone bias in near-fire smoke plumes sampled by the aircraft but significantly enhances ozone downwind when Canadian smoke plumes reach cities in Washington state, Utah, Colorado, and Texas. Using multi-platform observations, we identify the smoke-influenced days with daily maximum 8-h average (MDA8) ozone of 70-85 ppbv in Spokane, Salt Lake City, Denver and Dallas. On these days, mixing of wildfire smoke into urban pollution enhance simulated MDA8 ozone by 10–20 ppbv.