Over the past few decades, the metal oxide-based thin-film sensors have been widely studied and commercialized for gas sensing applications but their poor sensing response and high temperature operation (>300°C) are the issues to be addressed. Here, we demonstrate the MoS 2 decorated α-Fe 2 O 3 thin film-based NO 2 gas sensor. The α-Fe 2 O 3 thin film was deposited on silicon substrate using RF magnetron sputtering technique at 6000C substrate temperature. The α-Fe 2 O 3 thin films were characterized using an X-ray diffractometer and a Scanning Electron microscope for structural and morphological characterizations. Further, we decorated the Fe 2 O 3 thin film using hydrothermally synthesized MoS 2 nanoparticles dispersed in ethanol via the drop-casting method to increase the response towards NO 2 gas. The MoS 2 decorated sensor shows a fast gas detection with the improved response of (ΔR/R a %) of ~69% at 150°C for 100ppm of NO 2 gas, which is 68% higher as compared to the pristine sample (~42%). The sensor shows a fast response time of ~34 sec and a moderate recovery time of ~95 sec. The decoration of MoS 2 nanoparticles has increased the surface to volume ratio and active sites and hence increased the number of gas molecules that can react with the surface of the sample. The sensor shows high sensitivity and selectivity towards NO 2 due to increased holes and reduced barrier height in MoS 2 /α-Fe 2 O 3 p-p heterojunctions.