This paper reviews the experimental and modeling work that has been carried out concerning the behavior of fiber-reinforced polymer (FRP) composites in fire since the 1980s. The first part focuses on the thermophysical properties and temperature responses, while the second considers thermomechanical properties and responses, which are significantly affected by the thermal exposure of the FRP material. Furthermore, the application of deformation-based or strength-based failure criteria enables the prediction of time-to-failure. If the fire exposure time is less than the time-to-failure, the post-fire behavior is of interest and the post-fire properties and their potential recovery after cooling are particularly addressed. This fundamental understanding obtained as a result of both modeling and experimental work makes a reliable endurance design for FRP structures in fire possible.