In this paper, a new method based on stimulated Brillouin scattering (SBS) combined with UV-visible absorption spectra for authenticating the quality class of olive oils is investigated. UV-visible absorption spectra of different classes of olive oils are measured. According to the number and location of measured absorption peaks, the quality class of different olive oils can be preliminary authenticated. On the basis of measured absorption spectra, the SBS spectra of olive oils at the different temperature conditions are collected, and then the variation of SBS frequency shifts with temperature is analyzed. The experimental results indicate that different classes of olive oils present the same variation tendency in SBS spectra: frequency shift decreases with the increase of temperature, but each class of olive oil has its own unique curve. By employing the method of SBS combined with UV-visible absorption spectrum, the quality class of olive oils can be authenticated efficiently and quickly.