Purpose <p>Magnetic nanocellulose fiber composites (MFNCs) offer an innovative approach to drug delivery due to their high therapeutic loading capacity, low cytotoxicity, and stimulus-triggered release using magnetic fields. However, achieving efficient tumor-targeted drug delivery remains challenging. MFCNs were synthesized through an in situ co-precipitation process using iron salts, followed by functionalization with 3-aminopropyltriethoxysilane to create amine-functionalized MFCNs (NH₂–MFNCs). Curcumin was loaded onto NH₂–MFNCs using passive loading, and Concanavalin-A was subsequently conjugated to create a targeted drug delivery system. The composites were thoroughly characterized using various techniques, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. Additionally, magnetic susceptibility tests were conducted to confirm their magnetic capabilities. XRD analysis confirmed successful conjugation of Con-A onto the nanocomposite surface, while DSC and BET analyses highlighted the thermal stability and porous nature (25.233&#xa0;m²/g) of the formulation. The drug release profile exhibited pH-sensitive behavior, optimal for tumor environments. Cytotoxicity assays showed significant inhibition of MCF-7 cells, inducing cell cycle arrest at the G1 phase, with an IC₅₀ value of 100&#xa0;µg/mL. The synthesized MFNCs exhibit promising potential as a biocompatible, tumor-targeted drug delivery platform. Their pH-responsive release, magnetic guidance, and significant anticancer activity highlight their applicability in advancing targeted cancer therapy.</p> Graphical Abstract <p></p>