The current emerging economy of the leather industry is primarily linear. Increasingly rigorous legislative specifications for environmental preservation in developed countries have created huge pressure for the leather industry. In light of international efforts to achieve the Sustainable Development Goals (SDGs), a circular bioeconomy approach has gained compelling traction in addressing waste management challenges in the leather industry. The concept of circular bioeconomy encourages recycling of wastes yielded from leather processing. However, as of now, there is still a lack of research on bioeconomy concepts in the leather industry context. Hence, the purpose of this study is to put forth the antecedents for circular bioeconomy practices (BEP) in the leather processing industry (LPI), along which a firm can enhance its sustainability. Seventeen antecedents of BEP have been identified from the extensive literature review and experts survey; and their effects on each other are assessed using a blended grey based decision-making trial and evaluation laboratory model. Four major antecedents such as sustainable infrastructure for leather industry, biodiversity, advancement in sustainable products, sustainability threshold levels for bioeconomy technologies are identified as the most crucial key antecedents for BEP in the context of the LPI. In the present study, six antecedents are identified as causal, whereas eleven antecedents are identified as effect group antecedents. The sustainable infrastructure for leather industry is identified as the most crucial driving antecedent in ensuring circular BEP. The findings of this study provide a structural decision support model to the industry managers, practitioners, and relevant stakeholders that assists in knowing the cause-and-effect group antecedents of BEP towards attaining sustainability in the supply chain.