Tb3+ doped LaB3O6 phosphors with various dopant concentrations are synthesized via the combustion technique. X-ray diffraction patterns showed that both undoped and Tb3+ doped LaB3O6 samples matched PAN-ICSD reference. Scanning electron microscope scans indicated random aggregation. To identify the TL features, TL glow curves of Tb3+ doped LaB3O6 samples at various dopant concentrations are investigated by using different optical detection filter combinations. LaB3O6:Tb3+ (5.0%) and IRSL-TL 565 nm are chosen as the most suitable sample and ideal detection filter combination. Following the preheating experiments, the TL maximum is noted at a temperature of around 265 °C with a heating rate of 2 °Cs−1. The experimental findings from the dose-response of LaB3O6:Tb3+ (5.0%) exhibits an acceptable linearity (b = 1.028 with R2 = 0.999) up to 300 Gy. According to the results of the short-term fading test performed at various time intervals up to a week, it was observed that the decrease in the intensity of the dosimetric peak is never higher than 12% for the preheated sample, respectively and a new spurious maximum appears at the higher temperature region. The thermal quenching (TQ) effect was observed when the variable heating rates were operated and TQ parameters were calculated. Various heating rates, TM–Tstop, initial rise, and computerized glow curve deconvolution techniques were used to detect the overlapping peak numbers and establish the kinetic parameters of preheated LaB3O6:Tb3+ (5.0%). Based on the findings, the TL properties of Tb3+ doped LaB3O6 make it a potential material for TL dosimetry applications.