A vehicle side body structure having a pillar member including an upper member and a lower member that is joined to the upper member and has a rigidity lower than the upper member, the pillar member partitioning a side part opening of a body into a front part and a rear part; a side door disposed adjacently to the pillar member; and an impact bar provided in the side door, in which a front end portion of the impact bar overlaps with both the upper and lower members in side view while the side door is closed. The upper member has a reinforcing member and the front end portion of the impact bar covers a region of the upper member in which the reinforcing member is present, a region of the upper member in which the reinforcing member is not present, and the lower member in side view.