A compound of Chemical Formula 1: wherein each X is independently N or CH, provided that at least one X is N; Y is O or S; each Ar is independently substituted or unsubstituted: C6-60 aryl or C5-60 heteroaryl containing N, O or S; each R1, R2, R3, and R4 independently is hydrogen, deuterium, halogen, cyano, or substituted or unsubstituted: C1-60 alkyl, C1-60 alkoxy, C2-60 alkenyl, C2-60 alkynyl, C3-60 cycloalkyl, C6-60 aryl, or C2-60 heteroaryl containing N, O or S, or two adjacent R4s combine to form a C4-60 aliphatic or aromatic ring; n1, n2, and n3 are each independently 0 or 1, and n4 is 1 to 4, provided that at least one of Ar is substituted with deuterium, or at least one of R1, R2, R3, or R4 is, or is substituted with, one or more deuterium; and an organic light-emitting diode including the same.