Steel multitiered braced industrial buildings exhibit seismic behavior different from that of conventional multistory braced frames because most of their mass is concentrated at the roof level and no floor diaphragm exists at the intermediate tier levels. Moreover, soil and foundation flexibility may alter their seismic response. Nevertheless, the combined influence of structural height and soil–structure interaction on the seismic fragility and collapse performance of these systems has received limited attention. In this study, three two-tiered steel braced industrial buildings with heights of 6, 8, and 12 m were modeled under fixed-base and soil–structure interaction conditions. Member nonlinearity, brace buckling and low-cycle fatigue, and soil–foundation flexibility represented by nonlinear Winkler springs were incorporated in OpenSees. Nonlinear static and incremental dynamic analyses were then performed using 22 FEMA P695 far-field ground motions, and seismic fragility curves and collapse-performance indices were derived. The results showed that the influence of soil–structure interaction became more pronounced as structural height increased. Its influence on collapse performance was limited, whereas more pronounced effects were observed at the slight and moderate damage states; therefore, it should be considered in the seismic performance assessment of these structures. both fixed-base and soil–structure interaction conditions. The adjusted collapse margin ratio increased with structural height, while soil–structure interaction caused only a limited reduction in the collapse margin.