In this article, the numerical investigations on a novel (ITO/CeO2/SnS/NiO/Mo) heterostructure of the SnS-based solar cell have been presented using SCAPS-1D simulation software. The main objective of the study was the exploration of the effect of NiO hole transport layer (HTL) on the performance of the proposed SnS-based heterojunction solar cell. The open circuit voltage of the proposed cell has been enhanced up to 345 mV after using NiO HTL which indicates a significant reduction of surface recombination velocity at SnS/electrode interface. Around 12.78% efficiency enhancement was observed after using NiO HTL in the SnS-based heterojunction solar cell, and an efficiency of 25.1% could be obtained from the proposed heterojunction solar cell. It was found that the cell performance depended on the carrier concentration and thickness of the CeO2 electron transport layer (ETL), SnS absorber layer, and NiO HTL, respectively. The effects of deep level defect density of the SnS absorber layer and interface defect density of NiO/SnS and CeO2/SnS on the cell performance ware also studied. These findings reveal that the NiO could be a promising HTL for the fabrication of low cost, high-efficiency SnS-based heterojunction solar cell.