An efficient copper-catalyzed/-mediated and 8-aminoquinoline-assisted arylselenylation of inert C-H bonds of (hetero)arenes with readily available diselenides has been reported. The reaction is scalable and tolerates a wide spectrum of functional groups to deliver diarylselenides in very high yields (up to 98%). Application of this methodology to the facile synthesis of thiophene-fused selenochromone was demonstrated.