This work reports a numerical investigation on the performance of Sb₂Se₃‐based thin‐film heterojunction solar cell using the solar cell capacitance simulator in 1D (SCAPS‐1D) program. Herein, inorganic tin sulfide (SnS) is introduced as a new hole transport material into the Sb₂Se₃ solar cell. The effects of several parameters such as thickness, doping, electron affinity, defect density, temperature, and resistances on the cell performances are analyzed. The proposed novel solar configuration that consists of Al/F:SnO₂ (FTO)/CdS/Sb₂Se₃/SnS/Mo reveals the enhanced photovoltaic performances by means of reducing carrier recombination loss at back surface. At an optimized Sb₂Se₃ thickness of 1.0 μm, the efficiency is boosted from 24.01% to 29.89% by incorporating an ultrathin 0.05 μm SnS hole transport layer (HTL) into the Sb₂Se₃ solar cell. The performances of the proposed device are also evaluated by varying defects at CdS/Sb₂Se₃ and Sb₂Se₃/SnS interfaces. Moreover, it is found that electron affinity larger than 3.5 eV of HTL as well as back contact metal work function ≥4.9 eV should be considered to attain better performance. The simulated results lead to suggest that introducing the SnS material as a potential HTL candidate would be useful to develop low‐cost and highly efficient thin‐film solar cells.