Unlike their bulk counterpart, CuxInyS quantum dots (QDs) prepared by an aqueous synthetic approach, show promising activity for photocatalytic hydrogen evolution, which is competitive with the state‐of‐the‐art Cd chalcogen QDs. Moreover, the as‐prepared CuxInyS QDs with In‐rich composition show much better efficiency than the stoichiometric ones (Cu/In=1:1). Indium summer: CuxInyS quantum dots (QDs) prepared by an aqueous synthetic approach are demonstrated to be promising candidates for photocatalytic H2 evolution. The In‐rich CuxInyS QDs show much better activity than stoichiometric CuInS2 QDs (Cu/In=1:1) and are comparable to the state‐of‐the‐art Cd chalcogen (CdS, CdSe, and CdTe) QDs for H2 generation under visible‐light irradiation.