Today's companies are adopting a sustainable strategy, often in a reactive manner, to respond to customer demands, stakeholder concerns, and compliance with regulatory requirements, while seeking to proactively maintain a strong standing in the future market. This article explores the synergies between Industry 5.0 technologies and Green Lean Six Sigma (GLSS), highlighting how their integration can catalyse sustainable transformations in manufacturing. The study combines a literature review with empirical survey conducted across companies in various industrial sectors. The objective is to identify and examine potential synergies between Industry 5.0 technologies and Green Lean Six Sigma tools to improve the environmental impact of manufacturing companies. The results highlight the importance of Industry 5.0 technologies in boosting the efficiency of GLSS, thereby promoting more sustainable manufacturing practices. Key areas of synergy include sustainable process optimization, energy efficiency, sustainable personalization, data analytics for sustainability, and sustainable innovation. This article emphasizes the mutual benefits of integrating Industry 5.0 technologies with the Green Lean Six Sigma methodological framework. This combination reduces the consumption of materials and resources, improves energy efficiency, and stimulates innovation in favor of eco-responsible production. It calls for an integrated approach, considering technology, human resources, and processes, to enable manufacturing companies to achieve optimized operational performance while contributing to environmental sustainability.