<p>Eco-innovative methodologies are crucial for achieving sustainability by integrating environmental considerations into the innovation process. The study conducts a systematic literature review of eco-innovation methodologies, focusing on approaches such as life cycle assessment (LCA), environmental management systems (EMS), eco-design, and circular economy frameworks. Using Scopus-indexed journal articles from 2008 to 2024 (15 years), a total of 291 papers were initially retrieved, and 130 were selected based on relevance to eco-innovation methodology, peer-reviewed publication status, and language. Citation impact and methodological robustness were evaluated during the analysis phase, not as initial filters. The findings of this study highlight the evolution of eco-innovation research, the dominance of certain methodologies, and geographical research disparities. We critically assess the advantages, limitations, and industry applications of each methodology, contributing to the field by providing a comparative framework for future research. This study also identifies underrepresented yet promising methodologies such as Soft Systems Methodology (SSM), Causal Loop Diagrams (CLD), Sustainability Balanced Scorecard (SBSC), and Ecological Footprint Analysis, which may offer a broader comparative foundation for future research. Furthermore, recent advances in artificial intelligence (AI) applications are integrated into the discussion, illustrating how machine learning and data-driven tools are transforming life cycle assessment (LCA) modeling, real-time environmental management system (EMS) monitoring, and generative eco-design processes.</p>