<p>Organic pollutants such as dyes, nitro compounds, and halogenated substances are highly toxic, persistent, and often resistant to natural degradation. Therefore, the development of cost-effective, reusable, and environmentally friendly catalysts for the mitigation of organic pollutants is both urgent and essential. This article presents a comprehensive overview of cellulose-supported <i>3d</i>-transition metal nanocatalysts developed for environmental remediation, focusing on their synthesis, efficiency, and reusability in the degradation of hazardous organic pollutants. It highlights the use of cellulose-based supports, such as carboxymethyl cellulose and cellulose acetate, to enhance the stability and catalytic performance of metal nanostructures, including Fe, Co, Ni, Cu, and bimetallic combinations like Ni–Fe and Cu-Fe. The catalysts demonstrated significant efficacy in reducing toxic compounds like various nitrophenols, dyes, and organohalides, and pharmaceuticals, achieving high reduction rates and maintaining activity across multiple recycling cycles. The document also discusses the kinetics of these reactions, emphasizing pseudo-first-order behavior, and the impact of various parameters such as temperature, pH, and catalyst composition on performance. Additionally, it explores the mechanisms underlying the catalytic processes, including electron transfer and the role of reducing agents. Overall, this work underscores the potential of cellulose-supported nanocatalysts as effective and sustainable solutions for mitigating environmental pollution.</p> Graphical abstract <p></p>