Spatially resolved surface photovoltage spectroscopy (SRSPS) was employed to obtain direct evidence for highly anisotropic photogenerated charge separation on different facets of a single BiVO4 photocatalyst. Through the controlled synthesis of a single crystal with preferentially exposed {010} facets, highly anisotropic photogenerated hole transfer to the {011} facet of single BiVO4 crystals was observed. The surface photovoltage signal intensity on the {011} facet was 70 times stronger than that on the {010} facets. The influence of the built‐in electric field in the space charge region of different facets on the anisotropic photoinduced charge transfer in a single semiconductor crystal is revealed. Spatially resolved surface photovoltage spectroscopy (SRSPS) was employed to obtain first direct evidence of highly anisotropic photogenerated charge separations on different facets of a single BiVO4 photocatalyst. The results provide guidance to optimizing the performance of photocatalysts and solar cells.