This review discusses recent developments in the synthesis, properties, applications, and recycling of bio-based elastomers. Bio-based elastomers are derived from natural and renewable resources, offering a sustainable alternative to conventional plastics. The review highlights the importance of developing bio-based elastomers to reduce carbon emissions, avoid cross-contamination from fossil fuels, and create greener materials with biodegradable or compostable properties. The synthesis of bio-based elastomers is explored, with a focus on olefin metathesis as a novel and sustainable method. This method allows for the depolymerization or degradation of rubbers using natural resources such as essential oils, terpenes, fatty acids, and fatty alcohols. The use of chain transfer agents (CTAs) or donors of terminal groups in the main chain enables control over molecular weights and functional groups, resulting in new compounds, oligomers, and bio-based elastomers with added value for new polymer and material applications. Bio-based elastomers from natural and industrial rubbers, polyurethanes, polyesters, and polyethers are discussed, with an emphasis on their circular economy and sustainability. The review also explores the use of essential oils in bio-based elastomers, highlighting their potential as bio-resource materials for various applications. Terpenes are emerging as viable monomers for bio-based elastomer production, with β-myrcene being a common example. The polymerization of β-myrcene and β-ocimene with styrene using homogeneous titanium catalysts has shown promising results. Bio-based polyurethane elastomers are also discussed, with a focus on their synthesis from natural and renewable resources. The use of diols and polyols derived from algae, plants, animals, crustaceans, grains, cereals, and fruits is highlighted. The synthesis of bio-based polyurethane elastomers from industrial and natural rubbers is explored, with an emphasis on their elastomeric properties and applications. Bio-based and biodegradable polyester and polyether elastomers are discussed, with a focus on their synthesis from natural and renewable resources. These elastomers are highlighted for their potential in various applications, including biomedical, sensors, reconstruction, advanced materials, and drug delivery. The review also discusses the importance of circular economy and sustainability in the development of bio-based elastomers, emphasizing the need for resource efficiency and waste reduction. The review concludes that the development of bio-based elastomers is essential for reducing environmental impact and promoting sustainable practices in the plastics industry. The synthesis, properties, and applications of bio-based elastomers are discussed, with a focus on their potential to replace conventional plastics and contribute to a circular economy. The review highlights the importance of continued research and development in this area to achieve a more sustainable future.This review discusses recent developments in the synthesis, properties, applications, and recycling of bio-based elastomers. Bio-based elastomers are derived from natural and renewable resources, offering a sustainable alternative to conventional plastics. The review highlights the importance of developing bio-based elastomers to reduce carbon emissions, avoid cross-contamination from fossil fuels, and create greener materials with biodegradable or compostable properties. The synthesis of bio-based elastomers is explored, with a focus on olefin metathesis as a novel and sustainable method. This method allows for the depolymerization or degradation of rubbers using natural resources such as essential oils, terpenes, fatty acids, and fatty alcohols. The use of chain transfer agents (CTAs) or donors of terminal groups in the main chain enables control over molecular weights and functional groups, resulting in new compounds, oligomers, and bio-based elastomers with added value for new polymer and material applications. Bio-based elastomers from natural and industrial rubbers, polyurethanes, polyesters, and polyethers are discussed, with an emphasis on their circular economy and sustainability. The review also explores the use of essential oils in bio-based elastomers, highlighting their potential as bio-resource materials for various applications. Terpenes are emerging as viable monomers for bio-based elastomer production, with β-myrcene being a common example. The polymerization of β-myrcene and β-ocimene with styrene using homogeneous titanium catalysts has shown promising results. Bio-based polyurethane elastomers are also discussed, with a focus on their synthesis from natural and renewable resources. The use of diols and polyols derived from algae, plants, animals, crustaceans, grains, cereals, and fruits is highlighted. The synthesis of bio-based polyurethane elastomers from industrial and natural rubbers is explored, with an emphasis on their elastomeric properties and applications. Bio-based and biodegradable polyester and polyether elastomers are discussed, with a focus on their synthesis from natural and renewable resources. These elastomers are highlighted for their potential in various applications, including biomedical, sensors, reconstruction, advanced materials, and drug delivery. The review also discusses the importance of circular economy and sustainability in the development of bio-based elastomers, emphasizing the need for resource efficiency and waste reduction. The review concludes that the development of bio-based elastomers is essential for reducing environmental impact and promoting sustainable practices in the plastics industry. The synthesis, properties, and applications of bio-based elastomers are discussed, with a focus on their potential to replace conventional plastics and contribute to a circular economy. The review highlights the importance of continued research and development in this area to achieve a more sustainable future.