Deformable optoelectronic devices are emerging as critical technologies for wearable healthcare systems and next-generation display and energy harvesting platforms. Their practical deployment, however, remains limited by accelerated degradation under ambient conditions. Penetration of water vapor and oxygen accelerates the failure of moisture-sensitive layers, making encapsulation a key determinant of operational lifetime. A fundamental trade-off exists between barrier performance and mechanical stretchability: organic materials offer high compliance but poor moisture resistance, whereas inorganic barriers provide excellent impermeability but suffer from brittleness. Addressing these competing requirements demands an integrated approach that considers material selection and fabrication methodology. This review highlights recent advances in stretchable encapsulation technologies, encompassing organic, inorganic, and hybrid materials, and outlines the core requirements for practical operation: high impermeability, mechanical compliance, and optical transparency. By correlating emerging experimental results with these criteria, this review establishes a framework for designing encapsulation strategies that reconcile mechanical and barrier demands.