The transient absorption spectrum of o-iodobenzoyloxyl radicals was observed for the first time in acetonitrile using 1-(o-iodobenzoyloxy)-2-pyridone as a precursor. On the basis of the comparison of the spectra of o-halobenzoyloxyl radicals, it is proposed that the o-iodobenzoyloxyl radicals take a planar structure with a strong interaction between the radical center oxygen atom and the neighboring iodine atom.