We report an investigation on angle-cut beta barium borate (BBO) whispering gallery mode (WGM) resonators operating in the ultra violet (UV) wavelength range. A quality (Q) factor of 1.5 × 10(8) has been demonstrated at 370 nm. New upper bounds for the absorption coefficients of BBO are obtained from the Q factor measurements. Moreover, polarization rotations of WGMs in the angle-cut birefringent resonators are observed and investigated. To the best of our knowledge, this is not only the first reported demonstration of an angle-cut WGM resonator but also the first reported high Q WGM resonator in the UV region.