To provide a rubber composition for a sidewall, which can provide a tire having high cut resistance and, even after the occurrence of cut damage in a sidewall, advantageously suppressing the growth of the cut damage advancing toward the inside of a tire, and to provide a tire with a sidewall having high cut resistance.

A rubber composition for a sidewall of a tire is prepared by mixing a short fiber at a ratio of not less than 1 pt.mass and not more than 8 pts.mass based on 100 pts.mass of a rubber component and has a fiber aggregate index (FAI) of the short fiber of not more than 5%. In a tire, the rubber composition is applied to a sidewall thereof.