Metal nanoparticles (NPs) are incorporated in solar cells during the formation of front or back contacts to improve light absorption via the scattering of excitation light at their surface plasmon resonance (SPR) or localized SPR (LSPR). Here, we demonstrate LSPR-promoted improvement in the efficiency of CdS/CdTe solar cells fabricated by physical vapor deposition by incorporating different quantities of chemically synthesized 200-nm Au NPs in the CdTe layer. The J-V characteristics, external quantum efficiencies, absorption spectra, and cell efficiencies of these devices are compared. This study can guide future research on enhancing the CdS/CdTe solar cell performance using the plasmon effect.