The intermolecular alkylation of pyridine units with simple alkenes has been achieved via a photoredox radical mechanism. This process occurs with complete regiocontrol, where single-electron reduction of halogenated pyridines regiospecifically yields the corresponding radicals in a programmed fashion, and radical addition to alkene substrates occurs with exclusive antiMarkovnikov selectivity. This system is mild, tolerant of many functional groups, and effective for the preparation of a wide range of complex alkylpyridines.