A seat frame includes a cushion frame, a back frame, a recliner plate, a bracket arranged to be in contact with a side surface of each cushion side frame, a nut, an end nut, a bolt, and an end bolt. The bracket includes a nut fixing portion and a pipe fixing portion. The bolt is fixed to the nut in a state of being inserted through a bolt hole and a bolt insertion hole. The end bolt is fixed to the end nut in a state of being inserted through an end bolt hole.