The coil spring according to the present invention is a coil spring that is formed by spirally winding a wire rod and that includes a core that is elastically deformable and a reinforced fiber layer including reinforcing fibers wound around an outer circumference of the core and a thermoset resin that firmly adheres the reinforcing fibers to one another, wherein, in at least a part of a surface layer of the reinforced fiber layer, a content percentage of the reinforcing fibers on an inner circumferential side of the coil spring is larger than a content percentage of the reinforcing fibers on an outer circumferential side of the coil spring.