Postpartum body image is a critical aspect of maternal well-being, influenced by sociocultural, psychological, and relational factors. Theoretical models offer a broader framework for understanding these influences, whereas regression analyses identify specific associations. This systematic review aimed to identify theoretical models assessing postpartum body image and to examine its association with relevant constructs using regression analysis. A search was conducted of four databases (PubMed, EMBASE, Web of Science, and American Psychological Association) between August 2022 and March 2024. Studies including mothers over 18 years old, within 0–24 months postpartum, that applied theoretical models and/or regression analyses were included. Of 169 articles retrieved from databases and 1 identified through backward snowballing, 18 studies met the inclusion criteria. Three theoretical models were identified, and highlighted sociocultural influences, social support, and breastfeeding as key determinants of body dissatisfaction. Regression analysis identified association between postpartum body image and maternal weight, depression, mode of delivery, sexual function, breastfeeding, and social support. Given these influences, the review emphasizes the importance of adopting holistic approaches to support maternal well-being. Interventions addressing postpartum body image should integrate strategies that consider cultural expectations, promote adequate social support, and address physical and emotional health challenges, such as weight management and mental health care. PROSPERO (CRD42022352992).