Natural fiber-reinforced polymeric composites (NFRPCs) possess excellent potential for effective applications in many applications for various industries. There are significant advantages of using these materials over synthetic fibers, which apart from being biodegradable and environment-friendly also include excellent weight-to-stiffness and strength-to-stiffness ratios, low densities and light-weight structures, abundant availability, and others. Some of the limitations do include strength compared to their synthetic polymers, an aspect that has been widely addressed through hybridization. Additionally, natural fibers have traditionally faced issues regarding their flammability performance, limiting their applications where heat exposures are on the higher end. Natural fiber-reinforced hybrid composites also have similar issues, and therefore, it is imperative to observe and study the thermal properties and decomposition of the constituent fibers, polymers, and the derived composite under heat and fire. Another advantage of hybridization is also the ability to increase the fire performance of NFRPCs. The current chapter will primarily focus on the thermal behavior of the constituent of hybrid NFRPCs and the fire reaction and resistance properties of their composites, which can be used in both structural and non-structural applications within the built environment.