A seat slide apparatus for a vehicle includes an upper rail retaining a seat above the upper rail, a lower rail retaining the upper rail in a state where the upper rail moves relative to the lower rail, a rolling element arranged between the lower rail and the upper rail and a retaining member configured to retain the rolling element between the lower rail and the upper rail, the retaining member including a protruding portion having a top portion arranged to slidably contact with a rolling surface at which the rolling element rolls. The protruding portion includes a spreading portion extending from the top portion in an elongating direction, the elongating direction conforming to a path of the rolling element formed on the rolling surface, the spreading portion tapering to a sharp end form with an increasing distance from the top portion in the elongating direction.