Background: This narrative review explores the multidimensional impact of Mental Health Literacy (MHL) among military personnel, a population frequently exposed to high-stress environments and associated psychological risks. It aims to synthesize evidence on how MHL influences various individual, organizational, and social outcomes. Methods: A narrative review was conducted by analyzing relevant peer-reviewed articles published between 2015 and 2025. Comprehensive searches were performed across major databases, including PubMed, Web of Science, Scopus, the Scientific Information Database (SID), and MagIran. From an initial pool of 43 records, 8 duplicates were removed, leaving 35 articles for screening. After full-text assessment, 7 studies met the inclusion criteria. The review process followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)reporting guidelines, and the methodological quality of the included studies was appraised using the Mixed Methods Appraisal Tool (MMAT). Results: The results demonstrate that the impact of MHL in military personnel spans five core dimensions: (1) Education and Awareness, (2) Prevention and Treatment, (3) Performance Improvement, (4) Leadership and Social Support, and (5) Societal and Family Impact. Enhanced MHL not only reduces stigma and promotes help-seeking behavior but also improves stress management, early crisis identification, and timely intervention, contributing to overall psychological resilience. Conclusions: Strengthening MHL is essential for improving the quality of life, operational performance, and psychological well-being of military personnel. Commanders and military managers should prioritize developing and implementing targeted educational programs and interventions to foster mental health awareness and resilience.