This study maps the evolution of circular economy and sustainability research and examines the implementation challenges and governance requirements for supporting the transition toward a sustainable circular economy. Using a dual-method approach, this study combines bibliometric analysis and systematic literature review. Bibliometric data were collected from Scopus for the period 1990-2023 and refined to include 1,326 articles, reviews, and conference papers in business, management, accounting, economics, econometrics, and finance. The bibliometric analysis examines publication trends, globally cited articles, author productivity, citation influence, publication sources, affiliation and country scientific production, keyword co-occurrence clusters, and LDA-based thematic development. The systematic literature review synthesizes selected studies to identify implementation barriers and governance issues. The findings show rapid publication growth after 2015, with major contributions from leading journals, productive and influential authors, relevant institutions, and countries such as Italy, the United Kingdom, Spain, China, and the United States. The thematic results indicate that the field has shifted from broad conceptual and policy discussions toward implementation-oriented themes, including business model innovation, supply chain management, industrial performance, waste recycling, product design, and environmental assessment. The review identifies persistent challenges related to finance, data, technology, markets, coordination, social inclusion, and environmental protection. Based on these findings, this study proposes an integrated governance framework emphasizing financial feasibility, measurement capacity, technological and market readiness, collaborative coordination, social inclusion, and environmental protection.