In this research work, we report a new Mo(VI) Schiff base complex based on 1,3‐bis(4‐bromo‐2‐carboxyaldehyde phenoxy)propane, which was immobilized covalently on MnFe2O4 magnetic nanoparticles. The efficiency of the novel catalyst was investigated for the oxidation of olefins and organic sulfides. Under optimized conditions, the nanoparticle catalyst allowed selective epoxidation of cis‐cyclooctene, cyclohexene, and cis‐cyclodecane with 99% conversion in 10 min under solvent‐free condition with tert‐butyl hydroperoxide as oxidant. The catalyst also showed excellent ability for the oxidation of thioanisole, dimethyl sulfide and benzyl phenyl sulfide with a 99% conversion in 5 min and solvent‐less condition with H2O2 (30%) as oxidant. The recyclability of catalyst was also investigated in the oxidation of cyclooctene and methyl phenyl sulfide at least for 5 times.