This review surveys the application of graphene and its derivatives in organic solar cells, used as interfacial layers: including anode interfacial layers, cathode interfacial layers, and intermediate layers in a tandem device. Research work has be done for increasing the electroconductivity by reducing the oxide to partially oxidized graphene, as well as chemically modifying or making composite interfacial layer. Additionally, the researches on graphene derivatives and combined interfacial layers used as a cathode interfacial layer or an intermediate layer in the tandem device are discussed. Finally, this review suggests that graphene and its derivatives are potential to be used in perovskite solar cells.