Provided is an organic light emitting device comprising an anode; a cathode; and a light emitting layer between the anode and the cathode, wherein the light emitting layer comprises a compound of the following Chemical Formula 1 and a compound of the following Chemical Formula 2:
where A′ is a naphthalene ring fused with an adjacent ring and is unsubstituted or substituted with deuterium, and the other substituents are described in the specification. Organic light emitting devices in which a compound of Chemical Formula 1 and a compound of Chemical Formula 2 are co-deposited as a host for a light emitting layer exhibit reduced driving voltage and increased efficiency and lifespan.