The Fukushima Daiichi Nuclear Power Plant accident dramatically changed the lifestyle of residents who lived near the plant. We evaluated the association of metabolic syndrome (MetS) with specific lifestyle-and disaster-related factors in residents following the accident. Methods: This cross-sectional study included 20,920 residents who underwent both the Comprehensive Health Check and the Mental Health and Lifestyle Survey from June 2011 to March 2012. Associations between MetS and lifestyle-and disaster-related factors, including psychological distress (post-traumatic stress disorder [PTSD]), were estimated using logistic regression analysis, adjusted for demographic and lifestyle factors, in 2019. Results: MetS was present in 30.4% of men and 11.5% of women. There were significant differences in smoking, drinking status, and PTSD prevalence between subjects with and without MetS. Multivariable logistic regression analysis showed that age, quitting smoking, light to moderate drinking, and low physical activity were significantly associated with MetS. Moreover, PTSD was also significantly associated with MetS in women. Conclusions: Lifestyle-and disaster-related factors, including PTSD, were associated with MetS among subjects who lived near the Fukushima Daiichi Nuclear Power Plant accident.