Rare-earth-activated glasses have attracted research attention for radiation measurements for decades because of several practical merits, including their amenability towards mass production, large-volume fabrication, easing shaping, and their low cost. Various glass materials (e.g., borate and silicate glasses) have been characterized. In this study, photoluminescence, scintillation, and thermally stimulated luminescence (TSL) characteristics were observed for Pr3+-activated gallate glasses (69Ga2O3–20K2O–(11-x)La2O3–xPr2O3). Clear photoluminescence and scintillation peaks derived from the 4f-4f transitions of Pr3+ appeared in the range of 480–670 nm, where the photoluminescence and scintillation decay time constants attributable to the 4f-4f transitions of Pr3+ were on the order of microseconds. The thermoluminescence of these glasses was also investigated, where a broad TSL glow peak was detected at approximately 90°C. The lowest measurable dose limit is approximately 1 mGy. Moreover, isothermal decay curve analysis suggested that nine trap levels are associated with the TSL.