Provided is an organic light emitting device including a first electrode; a second electrode opposite to the first electrode; and a first organic material layer and a second organic material layer provided between the first electrode and the second electrode, wherein the first organic material layer includes a compound of Chemical Formula 1:






wherein:

at least one of Xa to Xc is N, and the rest are CR; and
Ar2 to Ar4 are each independently a substituted or unsubstituted aryl or heterocyclic group, and




the second organic material layer includes a compound of








wherein:
HAr is a substituted or unsubstituted heterocyclic group including at least one or more Ns;
L1 and L2 are each independently a direct bond or a substituted or unsubstituted arylene or divalent heterocyclic group; and
Ar1 is a direct bond, —O—, or a substituted or unsubstituted arylene or divalent heterocyclic group.