The present invention provides a run-flat tire that can improve both of ride quality and run-flat performance. The run-flat tire of the present invention comprises a sidewall-reinforcing layer prepared by using a rubber composition comprising non-metallic short fibers having an average fiber diameter of 1 to 100 μm and an average fiber length of 0.1 to 20 mm in an amount of 5 to 120 parts by weight on the basis of 100 parts by weight of a diene rubber, the non-metallic short fibers being oriented in the circumferential direction of the tire.