Metal sulfides are promising photocatalysts for efficient removal of organic pollutants in wastewater. However, the practical application of these catalysts is limited due to the fast recombination of charge carriers and poor catalyst stability. In this study, ternary reduced graphene oxide/SnS2/ZnFe2O4 (rGO/SnS2/ZnFe2O4) composites were synthesized by a hydrothermal process, and rGO content was optimized. The surface morphology, crystal structure, optical and electrochemical properties of rGO/SnS2/ZnFe2O4 composites were characterized. The adsorption capacity and visible-light photocatalytic activity of rGO/SnS2/ZnFe2O4 were influenced by rGO content with results revealing an optimal rGO content of 7 wt.%. The 7% rGO/SnS2/ZnFe2O4 composite demonstrated the highest visible-light photocatalytic activity with almost 100% 2-nitrophenol removal, which could be attributed to the efficient charge separation, and the formation of center dot O-2(-), h(+) and a few center dot OH radicals. The possible photocatalytic mechanism of rGO/SnS2/ZnFe2O4 composites was also provided based on the role of rGO and the energy bands of SnS2 and ZnFe2O4.