<p>The pursuit of sustainable alternatives in the dynamic landscape of the material science and engineering domains has grown intensely. Innovations in renewable materials to deal with the shortcomings of fossil-based resources and finding a safe and economical route for polymer waste by adopting a circular economy model (CEM) are two principal pathways to accomplishing our sustainability objective. The objective of this study is to provide a general overview of the latest developments in major bio-based and fossil-based polymers and plastics in terms of their production, utilization, and end-of-life considerations in light of their sustainability credentials. The approach of this review is based on a simple comparison of major impacts such as energy use, ecotoxicity, GHG (greenhouse gas) emission, water use, eutrophication, and ozone depletion during the entire life cycle of a polymer. This review also acknowledges the extensive work done in the bio- and polymer science field in its sustainability avenue, highlighting the immense prospects of bio-based alternatives derived from plants, animals, and microorganisms, along with the challenges of adoption on an industrial scale. The potential reduction of GHG emissions caused by biogenic or sequestered CO₂ in bio-based polymers encourages researchers to explore more viable alternatives. The burden of adequate research and validation of results, industry transparency, and political influence will always remain the key social responsibilities toward integrating a sustainable polymer into our lives.</p>