Hydrogen sulfide (H
2
S), an endogenous gaseous signaling transmitter, has gained recognition for its physiological effects. In this review, we aim to summarize and discuss existing studies about the roles of H
2
S in renal functions and renal disease as well as the underlying mechanisms. H
2
S is mainly produced by four pathways, and the kidneys are major H
2
S–producing organs. Previous studies have shown that H
2
S can impact multiple signaling pathways via sulfhydration. In renal physiology, H
2
S promotes kidney excretion, regulates renin release and increases ATP production as a sensor for oxygen. H
2
S is also involved in the development of kidney disease. H
2
S has been implicated in renal ischemia/reperfusion and cisplatin–and sepsis–induced kidney disease. In chronic kidney diseases, especially diabetic nephropathy, hypertensive nephropathy and obstructive kidney disease, H
2
S attenuates disease progression by regulating oxidative stress, inflammation and the renin–angiotensin–aldosterone system. Despite accumulating evidence from experimental studies suggesting the potential roles of H
2
S donors in the treatment of kidney disease, these results need further clinical translation. Therefore, expanding the understanding of H
2
S can not only promote our further understanding of renal physiology but also lay a foundation for transforming H
2
S into a target for specific kidney diseases.