In a moving body side section structure that includes a flow correction fin 1A that is provided on a side section of a moving body, the flow correction fin includes a first inclined portion 1Ae which is formed at a front end in the longitudinal direction of the moving body and in which a width in a width direction of the moving body is widened toward a rear side in the longitudinal direction of the moving body, and a second inclined portion 1Af which is formed further rearward than the first inclined portion 1Ae in the longitudinal direction of the moving body and in which the width in the width direction of the moving body is narrowed toward the rear side in the longitudinal direction of the moving body.