A facile and reproducible method for the synthesis of Ag₃PO₄/TiO₂ visible light photocatalyst has been developed to improve the photocatalytic activity and stability of Ag₃PO₄. The innovation of this method is to in situ deposit Ag₃PO₄ nanoparticles onto the TiO₂ (P25) surface forming a heterostructure. The improved activity of the Ag₃PO₄/TiO₂ heterostructured photocatalyst for the degradation of methylene blue (MB) and rhodamine B (RhB) under visible light irradiation is attributed to the increased surface area and enhanced absorption of MB and RhB. Furthermore, depositing Ag₃PO₄ onto the surface of TiO₂ facilitates electron–hole separation that leads to the elevated photocatalytic activity. The heterostructured Ag₃PO₄/TiO₂ photocatalyst significantly decreases the loading of noble metal Ag from 77 wt% to 47 wt%, thereby significantly reducing the cost for the practical application of Ag₃PO₄ photocatalyst.