Preserving a healthy environment of air, land, and water requires the treatment of dangerous organic effluents. Efficiently degrading hazardous pollutants requires low-cost, high-absorption visible-light-driven photocatalysts. Furthermore, the tin selenide exhibited a tiny band gap that promotes the faster recombination of electrons and holes, and rGO shows restacking morphology that reduces the surface area of the materials. Both issues have been resolved by adding the rGO into SnSe to make an rGO/SnSe resolving the restacking issue and narrowing the band gap. In this research work, we report a hydrothermally synthesize tin selenide (SnSe) sustained on reduced graphene oxide (rGO) nanosheets as photocatalysts. Our research focuses on the degradation of hazardous industrial malachite green dye. Our analysis suggests that the rGO/SnSe nanocomposite effectively degrades malachite green (MG) dyes by 95.52% compared to pure SnSe (83.52%). The rGO sheets facilitate electron (e-) excitation from the valence band (V.B) to the conduction band (C.B), which significantly enhances the photocatalytic performance. We also investigated the reusability of the photocatalyst and the mineralization activity of a malachite green (MG) pollutant to check the photocatalytic mechanism and stability. The reusability test indicates that rGO/SnSe exhibited excellent 86.45% stability. The scavenger’s analysis suggests that electrons (e-) and holes (h+) play a significant part in the photocatalytic mineralization of MG dye. Our research explores that the rGO/SnSe nanohybrid is a significant material for wastewater treatment, solar energy conversion as well as environmental restoration.