An organic light emitting device comprising: an anode, a cathode, a light emitting layer between the anode and the cathode, and a hole transport layer between the anode and the light emitting layer, wherein said hole transport layer may be a hole injection layer, a hole transport layer, or a layer that simultaneously injects and transports holes; and wherein said hole transport layer comprises a polymer containing a repeating unit represented by the following Chemical Formula 1, and an ionic compound containing an anionic group represented by the following Chemical Formula 2: wherein in Chemical Formula 1, L 1 is a substituted or unsubstituted C 6-60 arylene, each L 2 is independently a substituted or unsubstituted C 6-60 arylene, each Ar is independently a substituted or unsubstituted C 6-60 aryl, each R is independently hydrogen, deuterium, or a substituted or unsubstituted C 1-10 alkyl, wherein in Chemical Formula 2, n1 and n2 are each independently an integer of 1 to 3, with the proviso that n1+n2 is 4, Ar" 1 is R" is a photocurable group; or a thermosetting group, each R" 1 is independently hydrogen, halogen, or a C 1-60 haloalkyl, n3 is an integer of 1 to 4, Ar" 2 is each R" 2 is independently hydrogen, halogen, a C 1-60 haloalkyl, a photocurable group, or a thermosetting group, and n4 is an integer of 1 to 5; wherein the polymer further comprises a repeating unit selected from the group consisting of the following: an anode, a cathode, a light emitting layer between the anode and the cathode, and a hole transport layer between the anode and the light emitting layer, wherein said hole transport layer may be a hole injection layer, a hole transport layer, or a layer that simultaneously injects and transports holes; and wherein said hole transport layer comprises a polymer containing a repeating unit represented by the following Chemical Formula 1, and an ionic compound containing an anionic group represented by the following Chemical Formula 2: wherein in Chemical Formula 1, L 1 is a substituted or unsubstituted C 6-60 arylene, each L 2 is independently a substituted or unsubstituted C 6-60 arylene, each Ar is independently a substituted or unsubstituted C 6-60 aryl, each R is independently hydrogen, deuterium, or a substituted or unsubstituted C 1-10 alkyl, wherein in Chemical Formula 2, n1 and n2 are each independently an integer of 1 to 3, with the proviso that n1+n2 is 4, Ar" 1 is R" is a photocurable group; or a thermosetting group, each R" 1 is independently hydrogen, halogen, or a C 1-60 haloalkyl, n3 is an integer of 1 to 4, Ar" 2 is each R" 2 is independently hydrogen, halogen, a C 1-60 haloalkyl, a photocurable group, or a thermosetting group, and n4 is an integer of 1 to 5; wherein the polymer further comprises a repeating unit selected from the group consisting of the following: L 1 is a substituted or unsubstituted C 6-60 arylene, each L 2 is independently a substituted or unsubstituted C 6-60 arylene, each Ar is independently a substituted or unsubstituted C 6-60 aryl, each R is independently hydrogen, deuterium, or a substituted or unsubstituted C 1-10 alkyl, wherein in Chemical Formula 2, n1 and n2 are each independently an integer of 1 to 3, with the proviso that n1+n2 is 4, Ar" 1 is R" is a photocurable group; or a thermosetting group, each R" 1 is independently hydrogen, halogen, or a C 1-60 haloalkyl, n3 is an integer of 1 to 4, Ar" 2 is each R" 2 is independently hydrogen, halogen, a C 1-60 haloalkyl, a photocurable group, or a thermosetting group, and n4 is an integer of 1 to 5; wherein the polymer further comprises a repeating unit selected from the group consisting of the following: n1 and n2 are each independently an integer of 1 to 3, with the proviso that n1+n2 is 4, Ar" 1 is R" is a photocurable group; or a thermosetting group, each R" 1 is independently hydrogen, halogen, or a C 1-60 haloalkyl, n3 is an integer of 1 to 4, R" is a photocurable group; or a thermosetting group, each R" 1 is independently hydrogen, halogen, or a C 1-60 haloalkyl, n3 is an integer of 1 to 4, Ar" 2 is each R" 2 is independently hydrogen, halogen, a C 1-60 haloalkyl, a photocurable group, or a thermosetting group, and n4 is an integer of 1 to 5; each R" 2 is independently hydrogen, halogen, a C 1-60 haloalkyl, a photocurable group, or a thermosetting group, and n4 is an integer of 1 to 5; wherein the polymer further comprises a repeating unit selected from the group consisting of the following: