A novel MoS₂ nanosheet-coated ZnO heterostructure photocatalyst was successfully synthesized via a simple hydrothermal method. Two-dimensional MoS₂ nanosheets were intimately deposited onto ZnO surface to form an intimate function, which favors the charge-transfer and suppresses the recombination of the photogenerated electron–hole pairs between MoS₂ and ZnO, resulting in a significantly enhanced photocatalytic activity for hydrogen evolution. The photocatalytic activities of the MoS₂–ZnO composite photocatalysts with different MoS₂ contents for hydrogen production were systematically evaluated. The 1.00 wt% MoS₂–ZnO photocatalyst shows the highest H₂ production rate of 768 μmol h⁻¹ g⁻¹ in the presence of Na₂S and Na₂SO₃ as the sacrificial reagents, which is 14.8 times higher than that of pure ZnO. The photocatalytic activity of MoS₂ as a cocatalyst for H₂ evolution reaction is considerably higher than many noble metals such as Pt, Rh, Ru and Au, suggesting that MoS₂ could act as a potential substitute for noble metals in photocatalytic H₂ production systems. This work presents a noble-metal-free, highly-efficient, and stable MoS₂ cocatalyst to suppress the recombination of electron–hole pairs of ZnO, resulting in an enhanced photocatalytic hydrogen production activity.