<p>Precipitation-hardened and austenitic stainless steels are extensively used for various applications in aerospace research, mainly when a combination of excellent mechanical properties and high corrosion and heat resistance are required. When these stainless steel sheets are formed into various shapes, they are subjected to large plastic strains. Since stress triaxiality exists during formation of these sheets, plane stress condition cannot be assumed, and hence, an appropriate ductile damage model is necessary to accurately predict failure in FE simulations of sheet metal forming of these materials. In this work, the Bao and Wierzbicki (B-W) model was utilized for the determination of the fracture locus for 15–5 PH stainless steel and SS316Ti austenitic stainless steel sheets. The model parameters were determined from finite element simulation of uniaxial tension and in-plane shear tests by calibrating the predicted load–displacement curves with the experimental data. A combined Swift–Voce hardening law that exhibited better capability to capture the plastic response of these materials when compared to Swift law and Voce law was used to model the flow stress variation, especially at large strains in these sheet metals. The comparison of predicted and experimental force–displacement curves in uniaxial tension and in-plane shear tests validated the FE model by demonstrating excellent agreement between the experimental and FE simulation results. SS316Ti austenitic stainless exhibited significantly higher ductility than 15–5 PH stainless steel under both tensile and in-plane shear loading conditions, as evidenced by its much higher fracture strains across the stress states. The obtained results would be useful for the prediction of failure in these sheet materials by integrating the damage model with FE simulation.</p>