We have developed a unique plasmonic multiferroic photocatalyst by integrating silver nanoparticles (Ag NPs) with multiferroic bismuth ferrite (BiFeO₃–BFO) particulate and fiber nanostructures, and it showed a remarkable photocatalytic enhancement under direct sunlight. Sol–gel and electrospinning methods were employed to fabricate these nanostructures, and a modified chemical reduction method was formulated to decorate Ag NPs for an effective plasmon sensitization process. The observed redshift and wide optical absorption profile of plasmonic BFO nanostructures showed promise for enhanced absorption in visible light. The photocatalytic activity of these nanostructures was tested on the degradation of methylene blue under the irradiation of direct sunlight. Ag NPs-decorated BFO particulates and fibers significantly shortened the photocatalytic degradation by 2 h as compared to their parent BFO nanostructures. The observed phenomenon was attributed to a synergistic effect, wherein the localized surface plasmon resonance of Ag NPs augmented the sunlight absorption and trapped the excited carriers. These sensitized Ag NPs then facilitated the transportation of the charge carriers to the catalyst–dye interface, leading to a rapid generation of redox species that increased the degradation rate under sunlight irradiation.