A seat slide apparatus for a vehicle includes a first rail provided with a limiting portion extending from an end of each of the first folded back wall portions at a predetermined position in a longitudinal direction of the first rail, a second rail provided with a first through-hole extending through each of the second side wall portions and a second through-hole extending through each of the adjacent second folded back wall portions, the through-holes facing in the width direction at a predetermined position in the longitudinal direction of the second rail, and locking members, each of which is inserted through the first through-hole and the adjacent second through-hole and bridges the second side wall portion and the adjacent second folded back wall portion in the width direction and blocks a movement of the limiting portion in directions the first rail and the second rail move relative to each other.