<p>Water is an essential resource for sustaining life on Earth, yet the availability of fresh water is increasingly under threat. To address this challenge, innovative technologies are being developed, with solar energy emerging as a promising solution due to its abundant availability and cost-effectiveness. This chapter explores various solar-based water purification technologies, emphasizing their working principles and the comparative advantages they offer. Special attention is given to solar thermal technologies, discussing their diverse designs and operational mechanisms. These techniques provide an efficient and sustainable approach to meeting future water purification needs by leveraging solar energy.</p>