Background <p>Ovarian cancer (OC) exhibits significant ethnic and geographic disparities, with rising incidence in Asia contrasting global declines. While non-modifiable risk factors (e.g., genetics) are well-established, evidence for the role of modifiable factors like physical activity remains inconsistent, especially in Asian populations. This study systematically evaluates the association between physical activity, sedentary behavior, and OC risk in Asia.</p> Methods <p>We conducted a meta-analysis of seven studies (156,910 participants, 1,585 OC cases) from Japan, Korea, and China. Physical activity and sedentary behavior were assessed via self-reports. Meta-analysis was performed to pool RR estimates together with their 95% CI.</p> Results <p>Regular physical activity was associated with a 24% lower OC risk (RR = 0.76, 95% CI: 0.64–0.91; <i>P</i> = 0.002), despite high heterogeneity (I² = 75%). Sedentary behaviour was associated with a 55% higher OC risk (RR = 1.55, 95% CI: 1.23–1.96; <i>P</i> = 0.0002).</p> Conclusions <p>In Asian populations, physical activity may protect against OC, while sedentary behavior may elevate risk. These findings underscore the need for dual public health strategies: promoting exercise and reducing sedentary time. Future research should standardize exposure assessments and include diverse Asian subpopulations to refine prevention guidelines.</p>