Background: Service learning has been studied and applied in diverse educational settings for the past seven decades. While several research reviews have explored service learning from varied perspectives, none have employed bibliometric methods to investigate its evolution as a "knowledge base." Purpose: This review documents the evolving landscape and analyzes the intellectual structure of research on service learning. Methodology/Approach: The review analyzed 5,815 Scopus-indexed documents on service learning using descriptive statistics and science mapping. Findings: The review found that service learning constitutes a mature, rapidly expanding interdisciplinary field, with over 75% of the documents published since 2010. Despite its global scope, the literature remains concentrated in Western, economically developed nations. The intellectual structure of the literature encompasses four interconnected schools of thought: Service Learning Designs and Effects, Theory and Research, Implementation, and Engineering Education. Implications: The review highlights the importance of cross-pollination of theoretical perspectives and empirical findings in service learning research and practice. Subsequent research should prioritize the exploration of service learning in developing countries, the evaluation of diverse theoretical perspectives in studies of service learning designs and effects, and the use of mixed research methods in exploration of cultural, social, and political influences on service learning outcomes.