Au-WO3 nanocomposites (NCs) were used as a hole transport layer (HTL) to enhance the power conversion efficiency (PCE) of organic photovoltaic (OPV) cells. The photon absorption of the active layer in the OPV cells was increased due to the plasmonic effect caused by the Au-WO3 NCs, resulting in an enhanced short-circuit current density for the OPV cells with the Au-WO3 NC HTL. The value of the root-mean-square roughness of the Au-WO3 NC film was smaller than that of the WO3 NP film, resulting in a more efficient transport of holes from the active layer. The PCE of the OPV cell with an Au-WO3 NCs HTL with an Au NP concentration of 10 wt% was improved by 60.37% in comparison with that with WO3 nanoparticles. The enhancement of the PCE was attributed to both an increase in the efficiency of the hole transport at an Au-WO3 NCs HTL with an Au NP concentration of 10 wt%/active layer heterointerface and an enhanced photon absorption due to the localized surface plasmon resonance effect of the Au-WO3 NCs.