Purpose: This paper examines the global evolution of Lean Six Sigma research and its role in advancing sustainable practices. Maps the intellectual structure, thematic trends, and collaborative networks, highlighting its alignment with the United Nations Sustainable Development Goals. Design/methodology/approach: A bibliometric analysis is conducted using Scopus database, covering 2,148 peer-reviewed publications up to 2025. Performance indicators and science mapping techniques, including co-authorship, co-occurrence, and overlay visualizations, are applied through Bibliometrix and VOSviewer to identify influential scholars, institutions, countries, and thematic clusters. Findings: United States, India, and United Kingdom emerge as leading contributors, with Jiju Antony as the most prolific scholar. Thematic clusters are identified: one emphasizing industrial efficiency, sustainability, and digital transformation, and another focused on organizational management, service quality, and healthcare. Trends indicate a shift from traditional process standardization toward integration with Industry 4.0, big data analytics, and sustainability-driven practices. Practical implications: LSS acts as a strategic enabler of operational excellence and sustainable development, guiding practitioners in manufacturing, healthcare, and services. Social implications: LSS supports SDG 9, SDG 12, and SDG 3 by enhancing efficiency, resilience, and quality of life. Originality/value: This is the first comprehensive bibliometric mapping of LSS and sustainability, offering a foundation for global cross-sectoral applications.