wherein M in Formula 1 is Ir,

L₁ in Formula 1 is selected from ligands represented by Formula 2(1),

n1 is 1, 2, or 3, provided that when n1 is 2 or greater, two or more groups L₁ are identical to or different from each other,

L₂ in Formula 1 is selected from ligands represented by Formula 3A,

n2 is 0, 1, or 2, provided that when n2 is 2 or greater, two or more groups L₂ are identical to or different from each other,

L₁ and L₂ in Formula 1 are different from each other,

the sum of n1 and n2 is 3,

CY₁ in Formula 2(1) is a triphenylene,

Y₁₁ in Formula 3A is N,

Y₁₂ to Y₁₄ in Formula 3A is C,

CY₃ in Formula 3A is selected from a pyridine, a 5,6,7,8-tetrahydroquinoline, a 5,6,7,8-tetrahydroisoquinoline, a quinoline, and an isoquinoline,

CY₄ in Formula 3A is selected from a benzene, 1,2,3,4-tetrahydronaphthalene, a naphthalene, a carbazole, an azacarbazole, a fluorene, a dibenzofuran, a dibenzothiophene, a benzofuropyridine, and a benzothienopyridine,

a1 and a2 in Formula 3A are each independently an integer selected from 1 to 5,

R₁ to R₆ in Formula 2(1) are each independently selected from:

a hydrogen, deuterium, —F, C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; and

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, and —CFH₂;

Z₁ and Z₂ in Formula 3A are each independently selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, and a phosphoric acid or a salt thereof;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, and —CFH₂; and

a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉),

R₁₁ and R₁₂ in Formula 2 are each independently selected from:

deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, and a phosphoric acid or a salt thereof;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, and —CFH₂; and

a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉),

b1 in Formula 2(1) is selected from 0 to 3,

b2 in Formula 2(1) is selected from 0 to 4,

each of * and *′ in Formulae 2(1) and 3A indicates a binding site to M in Formula 1, and

at least one of substituents of the substituted C₃-C₁₀ cycloalkyl group, substituted C₁-C₁₀ heterocycloalkyl group, substituted C₃-C₁₀ cycloalkenyl group, substituted C₁-C₁₀ heterocycloalkenyl group, substituted C₆-C₆₀ aryl group, substituted C₆-C₆₀ aryloxy group, substituted C₆-C₆₀ arylthio group, substituted C₁-C₆₀ heteroaryl group, substituted monovalent non-aromatic condensed polycyclic group, and substituted monovalent non-aromatic condensed heteropolycyclic group is selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group and a phenyl group,

wherein Q₁ to Q₉ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid or a salt thereof, a sulfonic acid or a salt thereof, a phosphoric acid or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.