The COVID-19 pandemic has further aggravated the burden of mental health and presents an opportunity for public health research to focus on evidence-based interventions appropriate for populations residing in resource-constrained, post-conflict settings. Post-conflict settings have a higher service gap in mental health and fewer protective factors, such as economic and domestic security. Post-conflict settings are defined as locations where open warfare has ended but resulting challenges have remained for years. A strong emphasis on the engagement of diverse stakeholders is needed to arrive at sustainable and scalable solutions to mental health service delivery. This review discusses mental health service delivery gaps in post-conflict settings, highlights the urgency of the matter in the context of the COVID-19 pandemic, and provides recommendations for service gaps from evidence-based case study exemplars with an implementation science lens using the Consolidated Framework for Implementation Research (CFIR) as guide to improving adaptation and uptake.