An effort has been made to enhance the mechanical properties to a great extent by tuning the process parameters of the modified 9Cr–1Mo steel by carrying out its transformation into bainitic microstructure at isothermal temperatures of 460 °C for varying isothermal holding durations after austenitization at 1000 °C for an hour. Two sets of austempered specimens were made. One set was water quenched (Set-I), and the other set was air-cooled (Set-II) after austempering. The microstructural characterization of the processed steels was systematically carried out by optical and scanning electron microscopy (SEM). The Vickers hardness of the heat-treated specimens was found to be almost 1.5–2 times the hardness of the as-received tempered martensitic steel plates. The tensile strength was found to increase dramatically from ∼700 MPa to ∼1300 MPa after austempering as compared to the as-received tempered martensitic steel. Though the % elongation reduced slightly, a good amount of ductility was still maintained in the austempered steel specimens, allowing the steels to achieve an excellent combination of strength as well as ductility.