The so-called Z-scheme is a means of utilizing photo-induced electrons from a photosystem and has consistently motivated the design of synthetic photocatalytic systems. Although progress has been made in many pioneering studies on an inorganic-based Z-scheme, there have been no reports of a hybrid Z-scheme for an inorganic and a photosystem. Here, a hybrid Z-scheme is demonstrated by integrating a platinized photosystem I (PSI) and BiVO4 for hydrogen production. Up to now, PSI-driven systems have been limited to a one-step photoreduction reaction using sacrifi cial reductants. In this hybrid Z-scheme, step-wise charge separation in PSI and BiVO4 enables the production of hydrogen from only water under visible light. PSI and BiVO4 are conjugated via metal mediators to form an all-linked structure. The novel design exhibits potential for the development of a protein hybrid system for electrochemical devices, sensors, and a solar energy conversion system.