Background This study is a systematic review of barriers and facilitators of supply-side maternal, newborn, and child health (MNCH) service availability in the Democratic Republic of the Congo (DRC). Given gaps in understanding of the factors affecting supply-side service availability, authors reviewed the literature to describe the DRC’s landscape and inform future research and programming. # Methods Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, authors searched two databases and grey literature, using the Quality Assessment with Diverse Studies tool to assess quality. Authors identified key themes and used a narrative approach to analyze extracted data. # Results The search identified 2160 articles, with 26 meeting the inclusion criteria. Authors grouped them according to the following key themes: facility readiness, human resources for health (HRH), geography and transportation, conflict, financing, and governance. MNCH service availability was hindered by lack of supplies, logistical challenges, weak infrastructure, unmet staffing needs, HRH turnover, poor HRH distribution, career and payment obstacles, long distances to facilities and poor transportation, system strain and disruption due to conflict, low government expenditure, high out of pocket costs, fragmented stakeholders, and low government prioritization. Authors found facilitating factors in each key theme, including parallel supply chains and buffer stocks, proactive staffing policies, motivated HRH, novel transportation methods, health posts, concentrations of stakeholders in conflict zones, universal health coverage policies, provider payment reforms, stakeholder coordination, and horizontal integration efforts. # Conclusions The DRC faces substantial supply-side barriers to MNCH service availability. Progress towards the Sustainable Development Goals and better MNCH outcomes requires additional work to build on existing facilitators and investments in service availability. Additional research on demand-side factors and quality of care could inform these efforts.