Analysis of experimental ozone absorption spectra reveals that ultraviolet photolysis within the structured Huggins band yields extraordinary wavelength-dependent isotopic fractionation, oscillating between complete enrichment and complete depletion for changes of less than 2 nm in the excitation wavelength. Visible photolysis yields wavelength-dependent fractionation that varies from -300? to +300?. Photochemical modeling demonstrates photolysis contributes fractionation up to +45? to the heavy ozone anomaly in the middle stratosphere with measurable 17O and 18O isotopologue-dependent variations as a function of altitude despite the fact that the extraordinary photolysis-induced isotopic fractionation effect is dampened in the atmosphere due to the integration over all excitation wavelengths.