Yttrium (Y) doped aluminum nitride (AlN) thin films are prepared using reactive magnetron sputtering method in a nitrogen atmosphere at room temperature. Thermal annealing at a temperature of 900 °C is performed after the deposition for the homogeneity and removal of porosity in the films. The prepared samples are irradiated at a proton fluence of 1 × 1014 ions/cm2 with an energy of 335 keV. Electrical, optical, and structural characterization of as-deposited and irradiated films are performed using four-point probe method, Fourier transform infrared spectroscopy (FTIR), and x-ray diffraction (XRD) respectively, to determine the irradiation induced defects. The as-deposited samples are studied using Rutherford backscattering spectroscopy (RBS) for their stoichiometry and thickness of deposited films. It is concurred from the results that irradiation has impacted the crystallinity, electrical resistivity, and the optical properties of the thin films.