Postpartum weight retention (PPWR) is a strong predictor of obesity in later life with long term health consequences in women. Suboptimal lifestyle behaviours (e.g., diet and physical activity) contribute to PPWR. Postpartum lifestyle interventions are known to be efficacious in reducing PPWR; however, there are challenges to their successful implementation. To inform implementation, this narrative review provides an overview of the factors that contribute to PPWR, the efficacy of existing postpartum lifestyle interventions and key determinants of effective implementation using the Consolidated Framework for Implementation Research (CFIR) across intervention characteristics, implementation process, individual characteristics and outer and inner setting. We then suggest strategies to improve the translation of evidence into large-scale interventions that deliver on health impact in postpartum women. We have identified gaps that need to be addressed to advance postpartum lifestyle research, including the involvement of postpartum women and community members as key stakeholders for optimal reach and engagement, more complete reporting of intervention characteristics to optimize translation of evidence into practice, capacity building of health professionals and guidelines for postpartum lifestyle management.