Background <p>Maternal and neonatal morbidity and mortality remain disproportionately high in low- and middle-income countries (LMICs), partly due to inadequate intrapartum support, psychosocial stress, and disrespectful maternity care. Continuous labor support from birth companions or doulas offers a low-cost, high-impact intervention with demonstrated benefits in high-income settings, yet LMIC-focused evidence remains fragmented. This review synthesizes current evidence on the effects of birth companionship and doula care on maternal, neonatal, psychosocial, and implementation outcomes in LMICs.</p> Methods <p>A narrative review was conducted using structured searches of PubMed, Scopus, Web of Science, Lens.org, and WHO documents. Eligible studies were published between 2015 and 2025, conducted in LMICs or relevant to LMIC contexts, and reported empirical findings on continuous intrapartum support from informal companions, trained lay companions, or professional doulas. Data were synthesized thematically across maternal, neonatal, psychosocial, and implementation domains. A structured narrative appraisal was used due to heterogeneity in study design and outcome measures.</p> Results <p>A total of 27 studies were included in the narrative synthesis. These comprised 8 primary studies in LMICs, 6 high-income country (HIC) studies involving marginalized populations, and 13 systematic reviews. Continuous labor support was consistently associated with shorter labor, higher rates of spontaneous vaginal birth, reduced use of pharmacologic analgesia and oxytocin augmentation, and lower maternal anxiety and stress markers. Neonatal benefits included higher Apgar scores, earlier breastfeeding initiation, and enhanced mother–infant bonding. Psychosocial improvements were mediated through emotional reassurance, advocacy, improved communication, and culturally responsive support. Implementation barriers identified across LMIC studies included provider resistance, facility space limitations, inadequate training, and sociocultural constraints, while facilitators included community engagement, structured companion training, and phased integration into maternity systems. Evidence quality varied widely, with few LMIC-specific randomized trials and heterogeneous operational definitions of “continuous support.”</p> Conclusions <p>Evidence demonstrates that birth companions and doulas improve maternal well-being, early neonatal outcomes, and respectful maternity care in LMIC settings. Effective scale-up requires context-adapted implementation strategies, provider orientation, policy alignment, and rigorous LMIC-based trials assessing clinical outcomes, cost-effectiveness, and equity impacts. Companion-inclusive intrapartum care represents a feasible, low-cost strategy for strengthening quality and experience of maternity care in resource-limited health systems.</p>