Tropospheric ground-level ozone (O₃) is a global air quality pollutant and greenhouse gas. Long-term O₃ trends from 16 stations in Saxony, Germany, were compared over three periods, revealing worsened O₃ pollution over the last decade. O₃ formation has been volatile organic compound (VOC)-limited at traffic and urban sites for the past 20 years. To mitigate O₃ pollution, moderate nitrogen oxides and additional VOC controls, particularly in solvent use, should be prioritized in the coming years.