Objective: To understand the relationship between lifestyle and the comorbidity of myopia and overweight/obesity among primary and secondary school students, so as to explore precise strategies for the prevention of multiple comorbidities. Methods: From September to October 2023, a stratified cluster random sampling method was used to collect 1 853 students from 7 schools in Hongkou District, Shanghai. Information on co-occurrence of myopia and overweight/obesity among students was obtained through vision examination and physical examination. Univariate analysis was performed using the χ 2 test, and multivariate Logistic regression was conducted to explore the relationship of lifestyle with the comorbidity of myopia and overweight/obesity. Results: The comorbidity rate of myopia and overweight/obesity among primary and secondary school students was 20.4%. The comorbidity rate was higher in boys than in girls (25.3% vs. 15.4%), and higher among senior high school students (23.6%) than among junior high school students (20.4%) and primary school students (15.6%), with statistically significant differences ( χ 2= 27.96 , 12.30, both P <0.01). The distribution of the number of healthy lifestyles differed significantly by gender and school stage ( χ 2=12.72, 151.38 , both P <0.05). Multivariate Logistic regression analysis revealed that girls ( OR =0.52), daily breakfast consumption ( OR =0.66), and students who did not drink alcohol ( OR =0.63) were associated with a reduced risk of comorbidity of myopia and overweight/obesity among primary and secondary school students, while the risk was higher among senior high school students ( OR = 1.56) (all P <0.05). Conclusions The comorbidity of myopia and overweight/obesity is a prominent problem among primary and secondary school students in Hongkou District, and unhealthy lifestyles are associated with an increased risk of comorbidity. Future prevention and control efforts should take into account gender and school stage differences and adopt tiered and classified intervention strategies.