The formation and photoluminescence of Eu3+-doped Y2O3-SiO2 fabricated by using a mechanochemical method are investigated using X-ray diffractometry (XRD), scanning electron microscopy (SEM), thermogravimetric/differential thermal analysis (TG/DTA), and an Ocean Optics S2000 spectrometer. The crystallite size, calculated using the Williamson-Hall and Scherrer methods, decreased generally to 300 min, and the behavior of the internal strain increased. Three exothermic peaks, T p1, T p2, and T p3, from the TG/DTA, are 331.4, 640.5, and 815.3 °C, respectively. The weight reduction rates for the three peak temperatures are 6.25, 2.55, and 1.02%, respectively. The strongest PL intensity measured was for an annealing time of 2 h at annealing temperatures from 700 to 900 °C. Under 380 nm excitation, emission peaks were observed at 589, 612, 626, and 704 nm due to 5D o → 7F o , 5D o → 7F1, 5D o → 7F2, and 5D o → 7F3 transitions of Eu3+ ions, respectively.