Background:Community-led total sanitation (CLTS) is a widely applied rural behavior change approach for ending open defecation. However, evidence of its impact is unclear.Objectives:We conducted a systematic review of journal-published and gray literature to a) assess evidence quality, b) summarize CLTS impacts, and c) identify factors affecting implementation and effectiveness.Methods:Eligible studies were systematically screened and selected for analysis from searches of seven databases and 16 websites. We developed a framework to appraise literature quality. We qualitatively analyzed factors enabling or constraining CLTS, and summarized results from quantitative evaluations.Discussion:We included 200 studies (14 quantitative evaluations, 29 qualitative studies, and 157 case studies). Journal-published literature was generally of higher quality than gray literature. Fourteen quantitative evaluations reported decreases in open defecation, but did not corroborate the widespread claims of open defecation–free (ODF) villages found in case studies. Over one-fourth of the literature overstated conclusions, attributing outcomes and impacts to interventions without an appropriate study design. We identified 43 implementation- and community-related factors reportedly affecting CLTS. This analysis revealed the importance of adaptability, structured posttriggering activities, appropriate community selection, and further research on combining and sequencing CLTS with other interventions.Conclusions:The evidence base on CLTS effectiveness available to practitioners, policy makers, and program managers to inform their actions is weak. Our results highlight the need for more rigorous research on CLTS impacts as well as applied research initiatives that bring researchers and practitioners together to address implementation challenges to improve rural sanitation efforts. https://doi.org/10.1289/EHP1965