An organic light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode, the organic layer including an emission layer; a hole transport region between the first electrode and the emission layer; and an electron transport region between the emission layer and the second electrode. At least one of the emission layer and the electron transport region includes a condensed cyclic compound represented by one selected from Formulae 1-1 and 1-2: The organic light-emitting device including one or more of the condensed cyclic compounds according to embodiments of the present disclosure may have low driving voltage, high efficiency, high luminance, and long lifespan.