Deterioration of surface and ground water quality as a result of massive growth of population, industrialization and other anthropogenic activities has become an issue of serious concern across the globe, threatening the entire biosphere. Recently, adsorption technologies utilizing nano-engineered architectures have garnered the attention of the scientific community as a promising treatment methodology as they provide leapfrogging opportunities to develop next-generation sorbents with lower energy consumption and facile operation conditions. Within this context, iron oxide-based magnetic nanoscavengers have shown exuberant potential to remove noxious pollutants from hydrological systems due to their high removal efficiency, faster kinetics, low cost, easy accessibility, design flexibility and ability to regenerate the adsorbent. The present review article provides a one-stop-reference for researchers working worldwide in separation science as it encompasses all the literature reports on precisely engineered iron oxide-based nanoadsorbents which are exploited in sequestering organic, inorganic and biological toxic substances from different effluents. Besides, light has also been shed on several crucial factors influencing the sorption efficacy of the adsorbent that not only include applied conditions such as pH, concentration, etc. but also focus on the stability of designed materials and their affinity towards the concerned analyte. This article also outlines the concepts and terminologies associated with the solid phase extraction technique along with a brief discussion of synthetic and functionalization strategies to tailor the selectivity of the developed nanoscaled material towards a specific pollutant. Further, the review also attempts to present critical analysis of sorption efficacies of reported hybrid nanocomposites in detoxification of contaminated water streams that would be highly beneficial for the readers from the viewpoint of selecting a suitable sorbent. On a conclusive note, potential roadmaps are discussed to design future generation nanoscavengers that would possess key attributes for sustainable development, ultimately contributing to conserving our ecosystem and offering attractive prospects of being commercially viable. © 2021 The Royal Society of Chemistry.