A novel depolarization method for linearly polarized incident light that uses a liquid-crystal (LC) cell with randomly aligned hybrid orientation domains is theoretically described by use of Mueller matrix calculations. The depolarization effect of the incident linear polarization is confirmed with Stokes parameter measurements. The unique optical properties of the fabricated LC depolarizer are revealed; that is, the intensity of the transmitted light is independent of the rotation of the analyzer. The degree of polarization becomes zero when the retardation of the LC depolarizer coincides with a half-wavelength.