Cellulose is an eco-friendly, efficient, and suitable substrate for use as a coating material and support in the preparation of catalysts. Herein, MNP-cellulose-OSOH was prepared as an efficient heterogeneous catalyst composed of FeO nanoparticles covered with cellulose-OSOH and used for the synthesis of trisubstituted imidazoles. The catalyst was characterized by FT-IR, CHNS, ICP, PXRD, EDAX, elemental mapping, SEM, TEM, zeta potential, TGA, and VSM techniques. The catalytic activity was evaluated in the one-pot three-component synthesis of trisubstituted imidazole derivatives using benzil or 9,10-phenanthrenequinone, different aldehydes, and ammonium acetate in EtOH solvent at 80 °C over 30 min. The yields of products were excellent, in the range 83-97%. The catalyst showed outstanding catalytic performance toward heating conditions and good reusability. Also, this methodology had several advantages, such as simple procedures, short reaction time, excellent yield, simple workup, and mild reaction conditions.