Photo-induced charge transfer and photo-excited hot spots at nanoscale of graphene on single Ag nanoparticles (NPs) are inferred from the evolution of the Raman G-peak of graphene with the exciting laser power. Raman spectra of graphene attached to single Ag NPs on Si reflecting semiconductor and on quartz transparent dielectric substrates were investigated. It is demonstrated that optically-driven enhanced electron-phonon and phonon-phonon coupling define two regimes of the G-peak dependence with increasing the laser power. Optically controlled charge transfer at the nanoscale regime in graphene on single Ag NPs can meet the demands for future optoelectronic devices that require controllable doping with improved sensitivities, e.g. “light-gated” transistors. In addition, light tuning of the electron-phonon/phonon-phonon coupling opens up new ways for solar cell and energy harvesting technology.