Asphalt modification is one of the most effective tools to improve the performance and durability of flexible pavements that are exposed to heavy traffic and varied temperatures. Among various asphalt modifiers, bio-modifiers received great attention from various parts of the globe due to their potential in enhancing asphalt performance and having zero environmental impacts. In this direction, Rice Husk Ash (RHA), a large-scale by-product of rice manufacturing is found to be a potential bio-base asphalt modifier. Thus, the main objective of this study was to investigate the effect of RHA modification on asphalt performance. As a first step, the physio-chemical characterization of RHA under this study’s scope was analyzed at the micro-level. Base asphalt of viscosity grade, VG10 was modified with RHA at dosages of 10, 20, and, 30%. The performance of modified asphalt was determined by conducting conventional consistency tests including, penetration, softening point, and viscosity. The temperature susceptibility of RHA-modified asphalt was investigated from the A-VTS plot. Moreover, one-way ANOVA was conducted to understand the significance of RHA on asphalt properties on a deeper level. The research results indicated that RHA is enriched with micro-pores and silica, which improved asphalt adsorption and thermal stability. This was evident in the improved consistency, A-VTS plot, and ANOVA results. Overall, it can be concluded that RHA has great potential in enhancing the performance of asphalt at high pavement temperatures, resulting in long-life rut-resistant pavements. Moreover, the utilization of RHA as an asphalt modifier encourages sustainable pavement systems.