An extended tight-binding model that includes up to third-nearest-neighbor hopping and a Hubbard mean-field interaction term is tested against ab initio local spin-density approximation results of band structures for armchair- and zigzag-edged graphene nanoribbons. A single tight-binding parameter set is found to accurately reproduce the ab initio results for both the armchair and zigzag cases. Transport calculations based on the extended tight-binding model faithfully reproduce the results of ab initio transport calculations of graphene nanoribbon-based systems. ; Peer reviewed