Perovskite lanthanum chromate (LaCrO3) has been widely investigated for applications as functional material, its properties can be finely tuned through doping. This study explores the effect of Al3+ doping on the structure and electrical properties of La0.9Sr0.1Cr1-xAlxO3 ceramics. Our findings reveal that Al3+ doping significantly influences the consistency of grain size and electrical transport properties of these ceramics. As x increases, the grain size decreases and obtains its minimum at x = 0.5. Compared to the undoped La0.9Sr0.1CrO3, Al3+ doping significantly reduces the resistivity. For x = 0.3, the resistivity obtains its minimum 142.60 Ω cm at −75 °C, while the B-value is reduced to 405 K. These results demonstrate the potential of Al3+ doping in enhancing the thermal sensing properties of LaCrO3 ceramics and understanding of semiconductor behavior for electron device applications.