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 comprises 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 Chemical Formula 2, and a phosphorescent dopant represented by Chemical Formula 3: 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, and 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, Y 1 and Y 2 are independently a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C30 heterocyclic group, 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, and m is an integer ranging from 0 to 2; wherein, in Chemical Formula 3, 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, iridium is bound to the ring B through a Ir-C bond, and 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 comprises 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 Chemical Formula 2, and a phosphorescent dopant represented by Chemical Formula 3: 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, and 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, Y 1 and Y 2 are independently a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C30 heterocyclic group, 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, and m is an integer ranging from 0 to 2; wherein, in Chemical Formula 3, 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, iridium is bound to the ring B through a Ir-C bond, and 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.