In this study, we developed a magneto-plasmonic enhanced mpLFIA assay by designing a novel nanoparticle system, mpGNS, which significantly improves colorimetric brightness and enhances LFIA performance through the synergistic effects of magnetic concentration and plasmonic enhancement provided by the gold nanostar shell surrounding the magnetic core. RVFV nucleoprotein was selected as a model analyte to evaluate the performance of the mpLFIA platform. Analysis of the colorimetric signal intensity at the test line revealed that mpGNS-3, characterized by its longest spikes and highest branch density, exhibited the highest analytical sensitivity. The limit of detection (LOD) for the RVFV nucleoprotein using mpGNS-3 was as low as 2.24 pg/mL, demonstrating a 1000-fold improvement in sensitivity compared to assays utilizing conventional GNP. Moreover, our mpLFIA method was successfully applied to spiked blood serum samples, demonstrating significant potential for practical applications. We envision that this mpLFIA could serve not only for RVFV nucleoprotein detection but also as a versatile platform for detecting other infectious diseases in clinical samples.