We report on the enhancement of magnetic properties of Er-doped GaN epilayer structures, grown by metal-organic chemical vapor deposition, with illumination from a light emitting diode. Single and multiple Er-doped epilayers were grown with Er concentrations up to ∼ 1021 cm-3. All samples exhibited hysteresis behavior at room temperature as measured by an alternating gradient magnetometer. When the samples were illuminated at a wavelength of 371 nm, an increase in saturation magnetization was observed for each sample. The percentage increase for multiple layer samples ranged from 10%-25% indicating possible device applications.