Nitrogen oxides (NOx) play an important role in the formation of tropospheric ozone and fine particulate matter. Although regulatory policies in Southeast Asia have successfully limited combustion sources of NOx emissions, fertilized cropland NOx emissions have become increasingly prominent. However, the amount and geographic distribution of NOx emissions from fertilized croplands over Southeast Asia remain largely uncertain. Here, we use a bottom-up spatial model that combines temperature dependence and the Yienger and Levy (YL95) scheme to quantify the spatiotemporal changes in crop-specific fertilized cropland NOx emissions at five-arcminute resolution (about 10 km) from 1980 to 2019. The results show a 4-fold increase in NOx emissions from fertilized croplands in Southeast Asia from 12.9 Gg N yr