In the last decades, many C-C bond-forming reactions have been developed, whereas less attention has been paid to the design of strategies involving C-C bond cleavage. We report a photocatalytic dehydroformylation sequence for the conversion of benzyl alcohols to arenes in a one-pot two-step process. Herein, the initial dehydrogenation of the benzyl alcohols to the corresponding benzaldehydes is combined with an additional decarbonylation step yielding arenes. As a result, a broad range of benzyl alcohols can be easily transformed in short times under mild photocatalytic conditions. The conducted mechanistic studies indicate that our cooperative hydrogen atom transfer (HAT)-cobalt system proceeds through the formation of & alpha;-alkoxy- and acyl radicals as key intermediates, involving concomitant syngas (CO+H2) generation. The combination of photoinduced hydrogen atom transfer (HAT) and cobalt catalysis gives access to a mild dehydroformylation sequence for the defunctionalization of benzyl alcohols to arenes. The transformation proceeds through a stepwise radical pathway, wherein benzylic and acyl radicals are generated as key intermediates. As a result, stable C-C bonds can be cleaved while generating concomitant syngas (CO+H2).image