To date graphene and graphene-derived materials have created an immense research interests due to its extraordinary physical, chemical, and physiochemical properties, which delineated graphene as an outstanding material for future electronics, optics, and energy-harvesting devices. Typically, graphene has high mobility and optical transparency along with excellent mechanical properties and chemical inertness. Single-layer graphene exhibits ultrahigh optical transmissivity (∼98%), which allows passing through wide range of light wave lengths, thus designated as an ever-reported material for an optically conducting window. Furthermore, graphene's optical, electrical, and electrocatalytic properties can be tuned by applying different chemical functionalization protocols, which make it one of the most suitable candidates for advanced applications in optoelectronic and energy-harvesting devices. This review is intended to summarize the most important experimental results from the recent publications concerning the fascinating properties of graphene electrodes and their applications in various types of solar cells. Furthermore, the state of the art of different graphene synthesis processes and functionalization for the applications in solar cells are also discussed in this review.