To better understand the impact of land-sea air masses interaction processes on ozone (O₃) pollution in Shenzhen, two typical land-sea interaction processes (long-range air masses transport and sea-land breeze (SLB) circulation) were analyzed based on ten years of observational ozone concentrations, meteorological dataset, meteorological reanalysis data and the HYSPLIT backward trajectory model. Long-range air masses were identified and further categorized into oceanic, coastal, and inland types according to trajectory pathways. The corresponding mean O₃ concentrations were (45.5±26.1), (71.3±33.7) and (68.4±30.6)μg/m³, respectively. Among them, coastal air masses exhibited the highest O₃ pollution levels, with a frequency of 39%, and showed particularly strong transport potential in autumn, making it a major source of O₃ pollution in Shenzhen. In addition, the SLB circulation further influenced O₃ concentration in Shenzhen. The annual frequency of SLB days in Shenzhen over the past 10 years was 18.8%, with the highest occurrence in spring and summer. O₃ concentrations on SLB days were significantly higher than that on non-SLB days, with an average annual difference of 9.6%, primarily due to low wind speeds, inversions, and recirculation conditions. The difference was most pronounced in autumn (12.28μg/m³) which could be attributed to favorable conditions, including clear and dry weather, lower background wind speeds, and a higher likelihood of SLB development. Overall, O₃ pollution in Shenzhen was strongly influenced by land-sea air masses interactions, particularly in autumn, which should be prioritized for mitigation.