This review explores the evolving landscape of thermoelectric materials, focusing on recent trends and innovations in ceramics, gel-like materials, metals, nanoparticles, polymers, and silicon. Thermoelectric materials have gained significant attention for their ability to convert waste heat into electrical power, making them promising for energy harvesting and cooling applications. The review highlights advancements in synthesis methods, doping strategies, and nanostructuring techniques that have significantly enhanced material performance. It provides a comprehensive analysis of controlled properties such as electrical conductivity, Seebeck coefficient, and thermal conductivity. The work also delves into the emerging applications of thermoelectric devices across various fields, including automotive, aerospace, wearable electronics, and industrial waste heat recovery. By offering forward-looking insights, the review outlines the challenges and future prospects of thermoelectric devices, emphasizing their potential to contribute to sustainable energy solutions and efficient thermal management systems. The review integrates current trends with future projections, providing a timely and comprehensive roadmap for researchers and engineers dedicated to advancing next-generation thermoelectric technologies.This review explores the evolving landscape of thermoelectric materials, focusing on recent trends and innovations in ceramics, gel-like materials, metals, nanoparticles, polymers, and silicon. Thermoelectric materials have gained significant attention for their ability to convert waste heat into electrical power, making them promising for energy harvesting and cooling applications. The review highlights advancements in synthesis methods, doping strategies, and nanostructuring techniques that have significantly enhanced material performance. It provides a comprehensive analysis of controlled properties such as electrical conductivity, Seebeck coefficient, and thermal conductivity. The work also delves into the emerging applications of thermoelectric devices across various fields, including automotive, aerospace, wearable electronics, and industrial waste heat recovery. By offering forward-looking insights, the review outlines the challenges and future prospects of thermoelectric devices, emphasizing their potential to contribute to sustainable energy solutions and efficient thermal management systems. The review integrates current trends with future projections, providing a timely and comprehensive roadmap for researchers and engineers dedicated to advancing next-generation thermoelectric technologies.