<p>Solar thermal collectors are a vital technology for the efficient utilization of solar energy. Their performance, however, is affected by complex heat transfer mechanisms and challenges associated with system integration. This review aims to provide a comprehensive analysis of recent advancements in heat transfer optimization for solar collectors, addressing a notable gap in the literature regarding systematic and multifaceted approaches to performance enhancement strategies. The manuscript discusses key technological innovations across various domains, including the application of nanofluids to improve thermal conductivity and optical properties, structural modifications such as optimized flow paths and fin configurations, the incorporation of phase change materials for thermal energy storage, advanced coating and filling techniques designed to minimize losses, algorithmic and machine learning models for performance prediction and control, and heat pipe technologies for efficient thermal transport. These innovations collectively lead to significant improvements in thermal efficiency, system stability, and operational flexibility. The review concludes that the synergistic integration of multiple technologies offers the greatest potential for next-generation solar thermal systems. Furthermore, future research should focus on intelligent control strategies, environmental adaptability, recyclable materials, and system-level lifecycle optimization to facilitate the transition of solar thermal energy from a supplementary to a primary energy source.</p>