Highly efficient visible-light-induced photocatalytic hydrogenation of nitrobenzene to aniline in water was observed over a Bi₂MoO₆ photocatalyst under N₂ atmosphere in the presence of (NH₄)₂C₂O₄ as a hole scavenger. 100% of the nitrobenzene was converted and the selectivity of aniline was ∼97% after 20 min of visible light irradiation (λ ≥ 400 nm). The Bi₂MoO₆ photocatalyst showed good catalytic stability for the hydrogenation of nitrobenzene. Further experimental results revealed that both (NH₄)₂C₂O₄ and the N₂ atmosphere were indispensable for the photocatalytic hydrogenation of nitrobenzene to aniline over the Bi₂MoO₆ photocatalyst. On the basis of the electron spin resonance analysis results, photoinduced electrons of the Bi₂MoO₆ photocatalyst were found to be the main active species for the hydrogenation of nitrobenzene. Moreover, a mechanism was proposed to explain the visible-light-induced photocatalytic hydrogenation of nitrobenzene to aniline over the Bi₂MoO₆ photocatalyst.