Provided is a vehicle seat having a high absorbing efficiency of impact energy upon rear end collision. The vehicle seat includes a pair of side frames that are arranged on the side, and lower frames and that connect lower portions of the pair of side frames to each other, in which a narrow portion including: a horizontal portion formed inside the pair of side frames along a longitudinal direction with a flexibility against a load equal to or more than a predetermined impact load, and an inclined portion extending from the horizontal portion via a bent portion inside the pair of side frames is formed on the lower frames.