The incorporation of plasmonic nanoparticles (NPs) into photovoltaic devices can increase light absorption and in turn improve solar cell performance. The graphene oxide-encapsulated gold NPs (Au@GO NPs) are designed and incorporated into photoanodes to demonstrate plasmonic dye-sensitized solar cells. The coupling between GO and the Au NPs has the beneficial effect of extending solar spectral utilization in the long-wavelength portion of the visible spectrum. In addition, GO encapsulation reduces charge recombination on the surface of the NPs and facilitates improved charge transport. As a result, champion devices with plasmonic photoanodes containing Au@GO NPs deliver a power conversion efficiency that reaches 9.1%. This corresponds to an enhancement in photocurrent and power conversion efficiency of 19 and 17%, respectively, compared to control devices.