The paper reviews recent developments in the synthesis, properties, applications, and recycling of bio-based elastomers. It highlights the increasing global production of plastics, particularly non-biodegradable and non-renewable polymers, which contribute to environmental pollution and waste accumulation. The focus is on the synthesis of bio-based elastomers from natural and renewable resources, such as rubber, polyurethanes, polyesters, and polyethers, to address these issues. Key methods and strategies include olefin metathesis, which allows for the depolymerization or degradation of rubbers using essential oils, terpenes, fatty acids, and fatty alcohols. These methods enable the control of molecular weights and functional groups, leading to the production of new compounds, oligomers, and bio-based elastomers with enhanced properties. The paper also discusses the circular economy and sustainability aspects of bio-based elastomers, emphasizing their potential to reduce carbon emissions, avoid fossil fuel contamination, and promote biodegradable and compostable behavior. Examples of bio-based elastomers and their applications in various fields, such as biomedical, sensors, bone reconstruction, advanced materials, and drug delivery, are provided to illustrate the practical benefits of these materials.The paper reviews recent developments in the synthesis, properties, applications, and recycling of bio-based elastomers. It highlights the increasing global production of plastics, particularly non-biodegradable and non-renewable polymers, which contribute to environmental pollution and waste accumulation. The focus is on the synthesis of bio-based elastomers from natural and renewable resources, such as rubber, polyurethanes, polyesters, and polyethers, to address these issues. Key methods and strategies include olefin metathesis, which allows for the depolymerization or degradation of rubbers using essential oils, terpenes, fatty acids, and fatty alcohols. These methods enable the control of molecular weights and functional groups, leading to the production of new compounds, oligomers, and bio-based elastomers with enhanced properties. The paper also discusses the circular economy and sustainability aspects of bio-based elastomers, emphasizing their potential to reduce carbon emissions, avoid fossil fuel contamination, and promote biodegradable and compostable behavior. Examples of bio-based elastomers and their applications in various fields, such as biomedical, sensors, bone reconstruction, advanced materials, and drug delivery, are provided to illustrate the practical benefits of these materials.