The luminescence and excitation spectra in the paramagnetic holmium-yttrium gallium garnet Ho0.2Y2.8Ga5O12 (Ho3+:YGG) have been studied experimentally at temperatures T = 80 and 293 K. Identification of the radiative 4f → 4f transitions observed between 5S2, 5F4, and 5I8 multiplets of the ground 4f(10)-configuration of Ho3+ in sites of D2 symmetry was performed on the base of the results of numerical crystal-field calculations. Analysis of the features observed in the measured magnetic circular dichroism and magnetic circular polarization of luminescence spectra at T = 80 K confirms the correctness of the symmetry characterization of the Stark levels for several multiplets of Ho3+ in Ho:YGG. Significant contributions from quasidoublet states in the 5S2, 5G5, and 5I8 multiplets explain the magnetooptical measurements of the 4f → 4f transitions under consideration.