Abstract Wildfires degrade urban air quality by transporting fine particulate matter (PM2.5 ${text{PM} }{2.5}$) and ozone (O3 ${mathrm{O} }{3}$) precursors. Such impacts are seldom quantified in the Southern Hemisphere. This study quantified contributions of wildfire emissions to ambient PM2.5 ${text{PM} }{2.5}$ and O3 ${mathrm{O} }{3}$ (ΔPM2.5 ${Delta }{text{PM} }{2.5}$ and ΔO3 ${Delta }{mathrm{O} }{3}$) across 22 urban monitoring sites in Queensland, Australia, in 2008–2023, using a counterfactual machine learning model. Wildfire‐impacted hours during fire‐active seasons (July–December) were approximately three times more frequent in 2018–2023 than 2008–2017. During wildfire‐impacted periods of the fire‐active seasons, the relative enhancement of PM2.5 ${text{PM} }{2.5}$ and O3 ${mathrm{O} }{3}$ due to wildfire emissions reached 160.5% and 33.2% at maximum, respectively. The ΔPM2.5 ${Delta }{text{PM} }{2.5}$ was controlled by the wildfire intensities and their atmospheric transport time. ΔPM2.5 ${Delta }{text{PM} }{2.5}$‐NO2 ${text{NO} }{2}$ ratio was used to indicate the interaction between wildfire emissions and local NOx ${text{NO} }{x}$ emissions. Daytime ΔO3 ${Delta }{mathrm{O} }{3}$ increased monotonically with higher ΔPM2.5 ${Delta }{text{PM} }{2.5}$‐NO2 ${text{NO} }_{2}$ ratios, indicating a stronger influence of wildfire emissions.