A seat slide apparatus for a vehicle includes first and second lower rails, first and second upper rails, first and second lock levers, first and second biasing members, first and second support brackets fixed to the first and second upper rails and including first and second support portions, an operation handle including first and second power transmission portions pressing the first and second lock levers so as to release the restriction of the movement of the upper rails relative to the lower rails against a biasing force of the biasing members, and a release lever rotatably connected to the first upper rail and rotating in association with a forward folding of a seat back of the seat to release the restriction of the movement of the upper rails relative to the lower rails by directly pressing the first power transmission portion.