From absorption spectra obtained at high resolution by coupling a Fourier transform spectrometer to a long-path multiple reflection cell the intensities of the O2 Herzberg bands (A3Σu+-X3Σg-, c1Σu-, A′ 3Δu-X3Σg-) have been studied at ambient temperature. The integrated cross section values are given for the lines of the (v′-0) bands in the A3ΣuPLU-X3Σg-, c1Σu--X3Σg-, and A′ 3Δu-X3Σg- transitions with v′ = 0-11, v′ = 2-19, and v′ = 2-12, respectively. The band oscillator strengths have been deduced and transition moments have been calculated. The total absorption values in the region of the Herzberg bands together with the photoabsorption values determined previously above the dissociation limit can be modeled by a single curve, in agreement with the continuity relationship of the cross sections through the dissociation limit.