Owing to its unique two-dimensional structure and extraordinary physicochemical properties, graphene oxide (GO) is considered an ideal support for developing highly efficient photocatalysts. In this study, a novel Ag2O/GO nanocomposite, as a visible-light-induced photocatalyst, has been fabricated by a simple solution route. The electrostatic interactions between positively charged Ag+ and negatively charged GO sheets are responsible for the formation of the Ag2O/GO nanocomposite. The anchoring of the Ag2O nanoparticles on the GO nanosheets was confirmed by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The photocatalytic degradation of Methylene Blue (MB) under visible-light irradiation was studied to evaluate the photocatalytic activity of the Ag2O/GO nanocomposites. Due to the enhanced adsorption capacity, the smaller size of the Ag2O nanoparticles, and the improved separation of electron–hole pairs after the incorporation with GO sheets, the Ag2O/GO nanocomposites showed enhanced photocatalytic activity compared with bare Ag2O nanoparticles. In addition, the kinetics of the photocatalytic degradation reaction and a plausible photocatalytic mechanism are presented. The results pave the way to the design of highly efficient visible-light-responsive photocatalysts for the removal of organic pollutants for water purification.