A high-temperature sensor using fiber Bragg grating (FBG) integrated with a transducer has been designed, developed, and tested. The transducing element furnishes temperature-dependent tensile strain on FBG by means of differential linear thermal expansion of two different materials—mild steel and stainless steel. The designed sensor is compact, cost effective, and measures temperatures between 20°C and 1000°C. The electrical means output of the sensor against applied temperature is found to be fitted with a second-degree polynomial. The achieved resolution at room temperature is 2°C and is found to be better when moving toward higher temperatures. However, by optimizing the materials and physical dimensions of the transducer, it is possible to improve the temperature range and performance of the sensor.