The reactivity of nonheme iron(V)-oxo intermediates toward aromatic C-H oxidation at -70 °C has been directly evaluated. The intermediates were generated upon the interaction of the ferric complex [(PDP∗)FeIII(μ-OH)2FeIII(PDP∗)](OTf)4 (4- PDP∗ = N,N′-bis(3,5-dimethyl-4-methoxypyridyl-2-methyl)-(S,S)-2,2′-bipyrrolidine) with peracetic acid in the presence of acetic or 2-ethylhexanoic acid. The second-order rate constants (k2) for the reaction of substituted benzenes with iron-oxo intermediates [(PDP∗)FeV O(OC(O)R)]2+ at -70 °C were determined (R = CH3, 3-heptyl). For more electron rich arenes, much higher k2 values were observed, increasing in the order nitrobenzene < acetophenone < chlorobenzene < benzene < toluene, in accordance with the electrophilic aromatic substitution mechanism. The catalytic oxidation of mono- and dialkylbenzenes with H2O2 proceeded with good efficiency (up to 36.5 TN per Fe atom) and high selectivity toward aromatic oxidation products (up to 91%).