【Objective】Elevated near-surface ozone (O3) concentrations have been shown to reduce methane (CH4) emissions from rice paddies. However, the underlying mechanisms regulating soil CH4 production remain poorly understood. Thus, this study aimed to decipher the mechanisms regulating soil CH4 production at different rice growth stages and identify the main controlling factors.【Method】In this study, a widely cultivated rice cultivar (Nanjing 9108) in the Yangtze River Delta was used to investigate the effects of elevated O3 on methane production processes. An open-top chamber (OTC) system was employed to simulate elevated ozone conditions, including ambient air (NF) and ambient air supplemented with O3 (NF40 + 40 nmol·mol-1 O3). Rhizosphere soils were collected at the typical growth stages of rice (the filling stage and the maturity stage) and subjected to microcosm incubation experiments. Root morphological traits, soil carbon components, microbial abundance, and methanogenic archaeal community composition were simultaneously analyzed to elucidate the regulatory mechanisms of O3 on CH4 production. 【Results】The results showed that elevated O3 reduced specific root length (SRL) and specific root area (SRA) during the filling stage of rice, while enhancing soil organic carbon stability during the maturity stage of rice. This simultaneously altered the community composition of methanogens, characterized by an increase in the relative abundance of hydrogenotrophic methanogens and a decrease in the relative abundance of acetoclastic methanogens. O3 elevation reduced CH4 production rates in paddy soils by 38.1%–46.8%, with decreased acetoclastic methanogenesis rates by 66.6%–68.1%. Conversely, CH4 production rates via hydrogenotrophic methanogenesis increased by 6.1%–24.7%.【Conclusion】This study provides a process-based understanding of how elevated O3 regulates methane production in rice soils through coupled changes in plant root traits, soil carbon stabilization, and methanogenic community structure, offering critical insights for predicting CH4 emissions from agricultural ecosystems under future O3 pollution scenarios.