A fullerene derivative comprising: a substituent represented by Chemical Formula 1, wherein, in Chemical Formula 1, X is S, Ar is a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, or a triphenylene ring, R 1 to R 3 are independently hydrogen, deuterium, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 heteroalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 heteroalkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C2 to C20 heteroalkynyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C3 to C30 heterocyclic group, a halogen, a cyano group, or a combination thereof, a, b, and c are independently an integer of 1 to 3, and *-* is a linking portion with a fullerene core, wherein hetero refers to one including one to three heteroatoms selected from N, O, S, P, and Si, and remaining carbons in one compound, functional group, or moiety, and wherein substituted refers to the replacement of hydrogen by a substituent selected from a halogen, a hydroxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C30 aryl group, a C7 to C30 arylalkyl group, a C1 to C30 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroarylalkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C15 cycloalkynyl group, a C3 to C30 heterocycloalkyl group, and a combination thereof. a substituent represented by Chemical Formula 1, wherein, in Chemical Formula 1, X is S, Ar is a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, or a triphenylene ring, R 1 to R 3 are independently hydrogen, deuterium, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 heteroalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 heteroalkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C2 to C20 heteroalkynyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C3 to C30 heterocyclic group, a halogen, a cyano group, or a combination thereof, a, b, and c are independently an integer of 1 to 3, and *-* is a linking portion with a fullerene core, X is S, Ar is a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, or a triphenylene ring, R 1 to R 3 are independently hydrogen, deuterium, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 heteroalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 heteroalkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C2 to C20 heteroalkynyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C3 to C30 heterocyclic group, a halogen, a cyano group, or a combination thereof, a, b, and c are independently an integer of 1 to 3, and *-* is a linking portion with a fullerene core, wherein hetero refers to one including one to three heteroatoms selected from N, O, S, P, and Si, and remaining carbons in one compound, functional group, or moiety, and wherein substituted refers to the replacement of hydrogen by a substituent selected from a halogen, a hydroxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C30 aryl group, a C7 to C30 arylalkyl group, a C1 to C30 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroarylalkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C15 cycloalkynyl group, a C3 to C30 heterocycloalkyl group, and a combination thereof.