Single crystal of Tm-doped LaCl3 (LaCl3:Tm3+) with the dimension of diameter 7 mm and length 55 mm was successfully grown using an in-house-developed Bridgman furnace. The grown crystal has the self-trapped exciton (STE) emission in the range of 300–500 nm along with the characteristic emissions corresponding to the 4f-4f transition of Tm3+ ions under X-ray excitation. The scintillation characterizations of the grown crystal were performed by pulse height spectra, scintillation decay time, as well as pulse shape discrimination studies under γ-ray and α-particle excitation sources. The LaCl3:Tm3+ crystal was found to have a high light yield (42,000 ± 4,200 ph/MeV) with 4.2% energy resolution under γ-rays excitation. Moreover, the pulse shape discrimination studied using 137Cs and 241Am as the radiation sources provided a good FOM value. The results conclude the LaCl3:Tm3+ single crystal to be a promising candidate for X-ray and γ-ray detection purposes.