<p>The increase in the global fear of resource scarcity, climate impacts, and depletion of the environment has accelerated focus on the circular economy (CE) as a solution to resilient development. Focusing on BRICS countries, this article examines how CE practices of renewable energy adoption, municipal waste recycling, and waste treatment and disposal affect resource efficiency (RE) in three aspects: material, energy, and climate efficiency from 2015 to 2024. Principal component analysis was done to build a composite CE index and panel fixed effects regression was applied for further analysis. Findings indicate that resource productivity improves significantly through CE and energy and carbon intensity decreases. Experts explain that renewable energy is the single CE strategy with the most promising effect, as it can increase productivity and reduce emissions. Recycling is key to material and climate efficiency, decreasing energy intensity. In waste treatment, the contribution to productivity tends to be more pronounced without much impact on energy and climate efficiency. The control variables show that GDP has positive impacts on productivity, but not on energy and carbon intensity or urbanization, which have harmful consequences in all aspects of efficiency, and government effectiveness has eminent positive impacts as it has close relationships with institutional quality. These findings confirm the suggestion that CE presents an opportunity to decouple economic growth and resource and emission patterns, and that it is a potentially effective strategic policy tool in the BRICS effort to achieve sustainability transitions. Policy implications emphasise the necessity to enhance the implementation of renewables, recycling facilities, and governance systems to utilise the advantages of CE to the fullest. The study is informative because the CE-efficiency connection has been little studied, and it provides insight into emerging economies in parts where global sustainable development agendas are missing.</p>