Solar light is an ideal energy source to overcome the crisis of energy shortage and severe environment problems. In the past decades, photocatalysis technology has aroused tremendous interests. As a layered structure ternary metal chalcogenide, zinc indium sulfide (ZnIn₂S₄) is a typical visible-light-responsive photocatalyst which has a tunable band gap for wider light absorption. Recently, ZnIn₂S₄ has been widely utilized in photocatalytic applications. Its photocatalytic performance is largely dependent on its structure, morphology and optical characteristics. This review first presented the crystal properties, the morphology characteristics as well as the electronic and optical properties of ZnIn₂S₄. Then, recent advances in the preparation and growth mechanisms of ZnIn₂S₄ micro/nano-structures were summarized. Furthermore, the modification methods for constructing efficient ZnIn₂S₄-based photocatalysts and their applications in hydrogen evolution, CO₂ reduction and pollutants removal were also emphasized in this review. Finally, the current challenges and the crucial issues of ZnIn₂S₄ and ZnIn₂S₄-based photocatalysts were proposed. It is expected that such a critical review could bring a better understanding of ZnIn₂S₄.