<p>Concentrating solar power (CSP) with parabolic trough collectors (PTC) remains one of the most mature and commercially viable technologies for medium- to high-temperature solar energy conversion. This review provides a comprehensive examination of PTC systems, covering their fundamental principles, geometrical design, optical and thermal mathematical modelling, component materials (mirrors, receivers, selective coatings), heat transfer fluids (including nanofluids and supercritical CO₂), solar tracking systems, hybrid CPVT-LFR configurations, industrial applications (heating, cooling, desalination), and economic realities. Particular attention is given to performance analysis methods, comparative evaluation of four mathematical models (with Model IV demonstrating the highest accuracy against experimental benchmarks), and recent advancements in passive heat-transfer devices such as heat pipes and thermosyphons. Key findings highlight PTC’s technical strengths, including high optical efficiency, dispatchability through thermal energy storage, and versatility across industrial sectors, while identifying persistent challenges related to capital costs, financing, and competition from photovoltaic systems. The synthesis of recent literature underscores that continued innovation in modelling accuracy, material durability, and system integration, supported by policies that value dispatchability, is essential for broader deployment. By consolidating current knowledge and critically evaluating technological and economic trade-offs, this review serves as a practical resource for researchers, engineers, and policymakers seeking to advance PTC-based CSP as a reliable contributor to the global renewable energy transition.</p>