Rising worldwide populations and changing weather patterns have intensified worries about a possible water crisis throughout the last 20 years. As a major health concern, the presence of heavy metals in wastewater demands prompt action to mitigate its effects. To tackle this critical concern, a multitude of cutting-edge technologies have been put into action. It is worth mentioning that nanotechnology has gained the attention of academics worldwide as a promising subject within this science. Researchers have looked at nano cerium oxide as a potential water filtration material. The redox characteristics and oxidation storage capacity of cerium oxide are highlighted in this chapter as being the inherent traits that make it efficient in technologies like filtration, adsorption, and Advanced Oxidation Processes (AOP). Additional alterations to ceria that improve its qualities include adding nonmetal and metal atoms to its framework and dispersing it on a suitable support. Presenting this study gives a glimpse into the technical trends shaping the future of creating environmentally beneficial ceria-based products. Current breakthroughs in the application of cerium oxide for wastewater treatment are summarized and examined in this chapter, which sheds light on their efficacy and potential. It explains the dangers of commonly detected heavy metals and stresses the need for effective filtering methods. Many different things can benefit greatly from cerium oxide and solid solutions. Its usage in water treatment techniques has become widespread.