A vehicle seat includes: a seatback frame including an outer side part frame, provided at an outer side in a width direction of a vehicle body, and an inner side part frame, provided at an inner side in the width direction; an outer side load transmission block protruding from the seatback frame towards an outer side in the width direction, and transmitting to the seatback frame, an impact load inputted from a side of the vehicle body; and a protrusion part protruding from a side surface of the outer side part frame towards an outer side in the width direction, wherein the protrusion part is fitted and fixed to a fitting hole provided on the outer side load transmission block.