Optical and IR photometry of the Seyfert class 1 galaxy Arakelian 120 covering the wavelength range from 0.36 to 3.5 microns is reported. The observed fluxes are found to consist of contributions of starlight from the surrounding galaxy, emission lines, thermal gas continuum, nonthermal radiation, and possible IR emission from dust. It is concluded that the observed fluxes can be regarded as consisting of a power-law-spectrum (spectral index of 0.9 + or - 0.1) component with a superimposed broad emission hump centered near a rest wavelength or 3500 A plus a component from the underlying galaxy which contributes no more than 30% of the observed flux at 1.25 microns.