The availability of high-quality, low-cost water to meet requirements of the human has become a major issue in the twenty-first century. Supply of fresh water systems throughout the globe are failing to keep up with increasing demand, which has also been made worse by human population growth, global warming, and other factors and decreasing water quality in recent years. No amount of emphasis can be placed on the significance of technological innovation in allowing integrated water resource management. Nanotechnology promises to improve water and waste-water treatment efficiency. Due to its unique features, including as very tiny size, high surface-area-to-volume ratio, the surface’s potential to be modified, good magnetic characteristics, as well as a high level of biocompatibility, the use of iron oxide nanoparticles has gotten a lot of interest. Iron oxide nanoparticles have been propose as nano absorbents and photo catalysts in various environmental cleanup methods for waste-water treatment. This study described the most recent iron oxide nanoparticles uses in waste-water treatment, as well as the gaps that have hampered their large-scale field usage. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.