This study examines how tolerance, defined as the competency to respect others, can be cultivated through pedagogical approaches within Early Childhood Education for Sustainability (ECEfS). It synthesizes empirical evidence on implementation and classifies effectiveness to inform practice. Guided by PRISMA-2020, the systematic review surveyed articles published between 2020 and 2024 in ERIC, Scopus, Web of Science, and Crossref. From 1932 identified records, 38 studies met the inclusion criteria and underwent thematic and impact-level analysis using a five-point Impact Level Framework. Frequently identified practical strategies included story-based learning, cooperative play, reflective discussion, and teacher role modeling; these consistently enhanced empathy, social responsibility, and inclusiveness among young children. Impact Level ratings indicate that narrative and hybrid approaches (Levels 4–5) yield greater and more sustained outcomes than passive or single-component interventions (Level 1). Integrating tolerance into ECEfS supports character formation and advances Sustainable Development Goals, notably SDG 4 (quality education) and SDG 16 (peaceful, inclusive institutions). By conceptualizing tolerance as a respect-for-others competency and presenting a measurable implementation hierarchy, the paper provides actionable guidance for educators, researchers, and policymakers who prioritize high-impact interventions.
Jumiatmoko et al. (2026) studied this question.