Provided is a run-flat tire having a substantially-crescent-shaped cross section, which makes it possible to achieve both durability at the time of run-flat travel and ride comfort at the time of travel at a normal inner pressure. A rigidity reducing portion that reduces a tire rigidity in the width direction extends in the circumferential direction on a surface of a tread rubber in an area located on the inner side than an end of a belt in the tire width direction and on the outer side than a road-contacting end in the tire width direction under a 75% load state.