Arsenic-contaminated water poses a serious global health threat, requiring the development of effective and economical remediation solutions. Nanotechnology-based technologies have emerged as a viable way to overcome the constraints of older approaches. This chapter opens with an overview of arsenic as a pollutant, including its health effects and ubiquity in wastewater. It then discusses nanotechnology and nanoparticles, highlighting their importance and benefits in Arsenic removal. Metal oxides, carbon-based nanostructures, and polymeric nanoparticles are among the nanomaterials that are being studied for arsenic adsorption. The synthesis procedures for these nanomaterials are discussed with a focus on strategies that maximize their efficiency. The chapter highlights the improved performance and economic viability of nanotechnology-based solutions through comparative examinations of various types and conventional Arsenic removal technologies. These nanomaterials’ photocatalytic performance is assessed, showing that they can simultaneously remove Arsenic and break down organic pollutants. Future research directions are highlighted, with an emphasis on improving the affordability, sustainability, and scalability of Arsenic removal techniques based on nanomaterials. This chapter demonstrates the potential to greatly reduce Arsenic contamination and enhance public health outcomes worldwide through creative nanotechnological treatments.