A run-flat radial tire including a carcass spanning between a pair of bead portions, a side reinforcement layer provided to tire side portions coupling the bead portion and the tread portion together, and a reinforcement cord layer. The reinforcement cord layer is provided at a tire radial direction outside of the carcass, includes cord inclined to a tire circumferential direction at an angle of inclination of from 60 degrees to 90 degrees, and is disposed such that, when the side reinforcement layer is projected along a tire radial direction, an overlap width P of the reinforcement cord layer overlapping with the side reinforcement layer has a length of 7.5% of a tire section height, or greater.