Magnetic iron oxide nanoparticles have attracted attention because of their idiosyncratic physicochemical characteristics and vast range of applications such as protein separations, catalysis, magnetic resonance imaging (MRI), magnetic sensors, drug delivery, and magnetic refrigeration. The activity of the catalyst depends on the chemical composition, particle size, morphology and also on the atomic arrangements at the surface. The catalytic properties of iron oxide nanoparticles can be easily altered by controlling the shape, size, morphology and surface modification of nanomaterials. This review is focused on the use of iron oxide as a catalyst in various organic reactions viz. oxidation, hydrogenation, C-C coupling, dihydroxylation reactions and its reusability/recoverability.