A clip and a tether clip of a pillar garnish fixing structure includes a shaft and a pair of engagement hooks opposing each other. Each engagement hook is connected to the shaft at a hook connecting portion. A deformation promoting portion is formed at each of a pair of shaft wall portions opposing each other in a diametrical direction perpendicular to a direction in which the pair of engagement hooks are opposed. Even when a thickness of the hook connecting portion is increased thereby increasing a strength of the engagement hook, the hook connecting portion is deformed so as to approach a center axis line so that the engagement hook can pass through a clip fixing aperture. As a result, both the strength of the engagement hook and a serviceability can be satisfied.