Removing excessive free radicals (FRs) by a synthetic chemical might give a clue for treatment of many iron-mediated diseases. Deferoxamine (DFO) can be one of the chemicals of choice for the clue. To investigate photoredox properties of DFO, its quenching effect on superoxide radical (O2), hydrogen peroxide (H2O2) and hydroxyl radical (OH) was examined using luminol and ortho-phenanthroline (ophen) chemiluminescence (CL) systems and UV–vis spectrophotometry. Stern–Volmer equation was also used for the CL kinetics. The observed quenching effect of DFO on CL/photon production in luminol and o-phen CL systems strongly confirmed the static arm of quenching properties of DFO on OH and H2O2, but much less pronounced on O2 ; the quenching property was maximal when iron was involved in the reaction systems. The Stern–Volmer plots in the designed photochemical reaction systems also confirmed a potent quenching effect of DFO on FR-mediated CL. Our study highlights strong photoreducing and antioxidant properties of DFO with huge quenching capacity on excessive FRs, and thus implies its promising prospects for therapeutic applications.