Light-controlled electrical behavior of polymer/nanoparticle hybrid system in ambient condition is demonstrated. By embedding gold nanoparticles (Au NPs) in a poly(3-hexylthiophene) (P3HT) matrix, the photoresponses of the nanocomposite films are enhanced. The electrical behavior of the P3HT/Au NPs nanocomposite transistors and inverters are tuned over a wide range in depletion mode. UV-visible absorption spectroscopy, ultraviolet photoelectron spectroscopy (UPS), and steady-state photoluminescence (PL) spectroscopy are used to analyze the nanocomposite films. The findings provide a better understanding of light-induced threshold voltage shifts of P3HT-based field-effect transistors and inverters and demonstrate their potential applications in electronic signal modulation for solution-processed integrated circuits.