An organic optoelectronic device comprising an anode and a cathode facing each other and an organic layer disposed between the anode and the cathode, wherein the organic layer includes at least one of a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer, and the light emitting layer includes a first host represented by Chemical Formula 1, a second host represented by a combination of Chemical Formula 2 and Chemical Formula 3, and a phosphorescent dopant represented by Chemical Formula 4 wherein, in Chemical Formula 1, X 1 is O or S, Z 1 to Z 3 are independently N or CR a, at least two of Z 1 to Z 3 are N, L 1 and L 2 are independently a single bond, or a substituted or unsubstituted C6 to C20 arylene group, A is a substituted or unsubstituted carbazolyl group, R 1 is a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group, R a and R 2 to R 4 are independently hydrogen, deuterium, a cyano group, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted C6 to C20 aryl group; wherein, in Chemical Formula 2 and Chemical Formula 3, Y 1 and Y 2 are independently a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group, adjacent two *'s of Chemical Formula 2 are linked with Chemical Formula 3, * of Chemical Formula 2 that are not linked with Chemical Formula 3 are independently C-L a -R b, L a, L 3, and L 4 are independently a single bond, or a substituted or unsubstituted C6 to C20 arylene group, R b and R 5 to R 8 are independently hydrogen, deuterium, a cyano group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C30 heterocyclic group; wherein, in Chemical Formula 4, Z 4 to Z 11 are independently N, C or CR c, the ring C is bound to the ring B through a C-C bond, indium is bound to the ring B through a Ir-C bond, X 2 is O or S, R c and R 14 to R 19 are independently hydrogen, deuterium, a halogen, germanium group, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C1 to C10 alkylsilyl group, a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C30 heterocyclic group, and n is an integer ranging from 1 to 3. an anode and a cathode facing each other and an organic layer disposed between the anode and the cathode, wherein the organic layer includes at least one of a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer, and the light emitting layer includes a first host represented by Chemical Formula 1, a second host represented by a combination of Chemical Formula 2 and Chemical Formula 3, and a phosphorescent dopant represented by Chemical Formula 4 wherein, in Chemical Formula 1, X 1 is O or S, Z 1 to Z 3 are independently N or CR a, at least two of Z 1 to Z 3 are N, L 1 and L 2 are independently a single bond, or a substituted or unsubstituted C6 to C20 arylene group, A is a substituted or unsubstituted carbazolyl group, R 1 is a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group, R a and R 2 to R 4 are independently hydrogen, deuterium, a cyano group, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted C6 to C20 aryl group; wherein, in Chemical Formula 2 and Chemical Formula 3, Y 1 and Y 2 are independently a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group, adjacent two *'s of Chemical Formula 2 are linked with Chemical Formula 3, * of Chemical Formula 2 that are not linked with Chemical Formula 3 are independently C-L a -R b, L a, L 3, and L 4 are independently a single bond, or a substituted or unsubstituted C6 to C20 arylene group, R b and R 5 to R 8 are independently hydrogen, deuterium, a cyano group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C30 heterocyclic group; wherein, in Chemical Formula 4, Z 4 to Z 11 are independently N, C or CR c, the ring C is bound to the ring B through a C-C bond, indium is bound to the ring B through a Ir-C bond, X 2 is O or S, R c and R 14 to R 19 are independently hydrogen, deuterium, a halogen, germanium group, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C1 to C10 alkylsilyl group, a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C30 heterocyclic group, and n is an integer ranging from 1 to 3.