The present subvolume provides evaluated infrared spectroscopic data on O3 (Ozone) and is dedicated to all available molecular constants in the electronic ground state, of the 18 isotopomers. It is made of separate chapters. The first one succinctly reports molecular theories and equations, based on which most of the evaluated data given in the other chapters are established. Title of each data chapter indicates which data is reported (vibrational states, vibrational energy, band centers, harmonic frequencies, anharmonic constants, rotational and centrifugal distortion constants, resonance coupling constants, potential energy function, force constants, dipole transition moment, integrated band intensity, line shape parameters…). The isotopic identification, the natural isotopic abundance, and the cited bibliographic references are also given in each data chapter.