A simple and inexpensive cobalt/triarylphosphine catalyst promotes aldimine‐directed hydroarylation of styrene with high branched regioselectivity to afford 1,1‐diarylethane derivatives in good yields under mild reaction conditions. The ortho ‐formyl group in the hydroarylation products is amenable to dehydrative cyclization, to give fused polycyclic aromatic hydrocarbons, as well as decarbonylative removal.