An organic light emitting device comprising: an anode; a cathode; and a light emitting layer interposed between the anode and the cathode, wherein the light emitting layer includes, one or more compounds represented by the following Chemical Formula 1, one or more compounds represented by the following Chemical Formula 2, and one or more compounds represented by the following Chemical Formula 3: in Chemical Formula 1, Ar 1 and Ar 2 are each independently a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing one or more selected from the group consisting of N, O and S, L 1 to L 3 are each independently a single bond; or a substituted or unsubstituted C 6-60 arylene, each R 1 is independently hydrogen; deuterium; a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing one or more selected from the group consisting of N, O and S, and a is an integer of 0 to 7, in Chemical Formula 2, X' 1 is N and X' 2 is O; or X' 1 is O, and X' 2 is N, any one of R' 1 to R' 7 is linked with the following Chemical Formula 2A, and the rest are each independently hydrogen; deuterium; a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing one or more selected from the group consisting of N, O and S, in Chemical Formula 2A, L' 1 to L' 3 are each independently a single bond; or a substituted or unsubstituted C 6-60 arylene, and Ar' 1 and Ar' 2 are each independently a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing one or more selected from the group consisting of N, O and S, in Chemical Formula 3, X" is O or S, and any one of R" 1 to R" 10 is linked with the following Chemical formula 3A, and the rest are hydrogen or deuterium, in Chemical Formula 3A, L" 1 to L" 3 are each independently a single bond; or a substituted or unsubstituted C 6-60 arylene, and Ar" 1 and Ar" 2 are each independently a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing one or more selected from the group consisting of N, O and S. an anode; a cathode; and a light emitting layer interposed between the anode and the cathode, wherein the light emitting layer includes, one or more compounds represented by the following Chemical Formula 1, one or more compounds represented by the following Chemical Formula 2, and one or more compounds represented by the following Chemical Formula 3: in Chemical Formula 1, Ar 1 and Ar 2 are each independently a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing one or more selected from the group consisting of N, O and S, L 1 to L 3 are each independently a single bond; or a substituted or unsubstituted C 6-60 arylene, each R 1 is independently hydrogen; deuterium; a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing one or more selected from the group consisting of N, O and S, and a is an integer of 0 to 7, in Chemical Formula 2, X' 1 is N and X' 2 is O; or X' 1 is O, and X' 2 is N, any one of R' 1 to R' 7 is linked with the following Chemical Formula 2A, and the rest are each independently hydrogen; deuterium; a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing one or more selected from the group consisting of N, O and S, in Chemical Formula 2A, L' 1 to L' 3 are each independently a single bond; or a substituted or unsubstituted C 6-60 arylene, and Ar' 1 and Ar' 2 are each independently a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing one or more selected from the group consisting of N, O and S, in Chemical Formula 3, X" is O or S, and any one of R" 1 to R" 10 is linked with the following Chemical formula 3A, and the rest are hydrogen or deuterium, in Chemical Formula 3A, L" 1 to L" 3 are each independently a single bond; or a substituted or unsubstituted C 6-60 arylene, and Ar" 1 and Ar" 2 are each independently a substituted or unsubstituted C 6-60 aryl; or a substituted or unsubstituted C 2-60 heteroaryl containing one or more selected from the group consisting of N, O and S.