© 2021 Elsevier Ltd. All rights reserved.In the present work, the effect of indium (In) doping on the various properties of the zinc oxide (ZnO) thin films was investigated. The pure and 5% In doped ZnO thin films have been synthesized via the successive ionic layer adsorption and reaction (SILAR) method on glass substrates. The X-Ray Diffraction (XRD) analysis clearly indicated the well-crystalline wurtzite structure of ZnO and 5% In-ZnO films. The Scanning Electron Microscopy (SEM) study depicted the formation of granular and nanoflower structures on the surface of the synthesized films. The band-gap energy and the grain size values of 5% In-ZnO were found to be 3.32 eV and 22.33 nm, respectively. Also, the indium incorporation into ZnO made a significant change on the structural, morphological properties, and enhanced the gas-sensing performance of ZnO host material.