The selective oxidation of primary alcohols to aldehydes by O ₂ instead of stoichiometric oxidants (for example, Mn ^VII , Cr ^VI , and Os ^IV ) is an important but challenging process. Most heterogeneous catalytic systems (thermal and photocatalysis) require noble metals or harsh reaction conditions. Here we show that the Bi ₂₄ O ₃₁ Br ₁₀ (OH) _δ photocatalyst is very efficient in the selective oxidation of a series of aliphatic (carbon chain from C ₁ to C ₁₀ ) and aromatic alcohols to their corresponding aldehydes/ketones under visible-light irradiation in air at room temperature, which would be challenging for conventional thermal and light-driven processes. High quantum efficiencies (71 % and 55 % under 410 and 450 nm irradiation) are reached in a representative reaction, the oxidation of isopropanol. We propose that the outstanding performance of the Bi ₂₄ O ₃₁ Br ₁₀ (OH) _δ photocatalyst is associated with basic surface sites and active lattice oxygen that boost the dehydrogenation step in the photo-oxidation of alcohols.