A battery module includes: a cell stack body; a pair of end plates disposed on a front surface and a rear surface of the cell stack body; and a fastening frame connecting the pair of end plates. The fastening frame includes; a pair of side frames disposed on the right surface and the left surface of the cell stack body. The pair of side frames each includes: a side frame body; a front turn-around portion that turn around the front surface of the cell stack body; and a rear turn-around portion that turn around the rear surface of the side frame body. The front turn-around portion and the rear turn-around portion each has a width in a front-rear direction larger than a width in a left-right direction of the side frame body.