The rise of nuclear power plants to meet escalating global energy needs has made environmental pollution including the contamination of uranium due to improper disposal of radioactive wastewater during uranium milling and mining processes. Adsorption, a water purification method known for its fast kinetics, high selectivity, and ease of use, has emerged as a popular choice for the treatment of radioactive wastewater. In response to the critical need for the purification of radioactive wastewater contaminated with U(VI), this review provides a comprehensive summary of the various types of materials, synthetic methods, and adsorption mechanisms used for the purification process. The materials are categorized into four main groups: organic, inorganic, composite/nanomaterials, and framework materials. To enhance the adsorption capacity for U(VI), researchers have explored physical and chemical modifications as well as the development of organic-inorganic hybrids. The improved adsorption performance resulting from these modifications is mostly attributed to electrostatic interaction, surface complexation, and ion exchange mechanisms. However, despite the present understanding of the processes involved, further research is still needed to fully determine the optimal approach for purifying contaminated radioactive wastewater.