> The rise in online-to-offline (O2O) take-out food consumption has become a global urban phenomenon. While links between general fast-food consumption and increased risks of overweight and obesity are well-documented, the specific relationship with O2O take-out food has not been thoroughly examined. This study aims to fill this research gap by investigating the impacts of take-out food consumption on the risks of being overweight and obese among urban residents. A cross-sectional online survey was conducted between April and July 2022. 716 adult respondents from the metropolitan areas of Shanghai and Suzhou were recruited. Being overweight and obese were measured using self-reported weight and height. Frequencies and preferences of O2O take-out food consumption behaviors were measured using the validated questions designed based on Food Frequency Questionnaires and Dietary Screeners, respectively. The International Physical Activity Questionnaire’s short form measured the physical activity level. Cronbach’s alpha and Expletory Factor Analysis were used to assess the reliability and validity of the O2O take-out food-related dietary questions. Binary logistic regression models are developed to examine associations between O2O take-out food consumption behaviors and being overweight or obese, adjusting for individual factors, physical activity level, and non-O2O take-out food consumption. The results indicated a direct correlation between frequent O2O take-out consumption and higher risks of overweight and obesity (odds ratio 1.087, 95%CI 1.068~1.106). The preference for ordering Western-style fast-food positively contributed to being overweight and obese (odds ratio 1.071, 95%CI 1.046~1.095). Conversely, a preference for Chinese-style fast food initially appeared to reduce these risks, although the association diminished when accounting for fruit and vegetable consumption. This study represents a pioneering exploration into the effects of O2O take-out food on overweight and obesity. The study results identified an association between the habitual use of O2O take-outs and an increased propensity for being overweight and obese.