Wastewater purification is a critical global challenge due to the increasing contamination of water resources by industrial, agricultural, and domestic pollutants. Tin dioxide (SnO2)-based materials have emerged as promising candidates for wastewater treatment due to their unique physicochemical properties, including high chemical stability, photocatalytic activity, and tunable surface characteristics. This chapter provides the recent advancements in SnO2-based materials for wastewater purification. The chapter discusses the most important synthesis methods and applications of SnO2 materials in wastewater purification specially adsorption and photocatalytic degradation processes. Furthermore, the mechanisms of pollutant degradation, challenges, and future perspectives are included. This chapter aims to provide valuable insights for researchers or readers interested in water treatment.