A vehicle seat, comprising: a joining unit; a cushion frame joined to a seat cushion, turnably supported on the joining unit about a third pivot portion, and fixed to the third pivot portion; a frame joined to a seat back and turnably supported on the joining unit; a walk-in member turnably supported on the joining unit about a first pivot portion, and having an input portion and an output portion with the first pivot portion located between the input portion and the output portion; a disengagement member turnably supported on the joining unit about a second pivot portion, the disengagement member having one end portion joined to the output portion via a rod, another end portion arranged at a position being at a right angle to the one end portion, and a pressing portion formed on the one end portion; the rod joining the output portion of the walk-in member and the one end portion of the disengagement member; and a tip-up locking member turnably supported on the joining unit about the second pivot portion, the tip-up locking member having one end portion contacting the pressing portion, another end portion formed on the one end portion in a bifurcated shape, and an engagement portion extending from the one end portion and the other end portion toward a front side; a spring suspended between the other end portion of the tip-up locking member and the joining unit, and constantly rotationally biasing the tip-up locking member about the second pivot portion in a counterclockwise direction; a movement hole provided in the joining unit; a stopper member joined to the cushion frame and capable of engaging with and disengaging from the engagement portion of the tip-up locking member, the stopper member moving inside the movement hole in response to turn of the cushion frame about the third pivot portion; and a biasing unit applying a rotational biasing force to the third pivot portion in the counterclockwise direction, wherein a forward tilting of the frame causes a turning of the walk-in member, the turning of the walk-in member causes a turning of the disengagement member, the turning of the disengagement member causes a turning of the tip-up locking member thereby disengaged from the stopper member, and then the cushion frame is tipped up by the rotational biasing force applied by the biasing unit. a joining unit; a cushion frame joined to a seat cushion, turnably supported on the joining unit about a third pivot portion, and fixed to the third pivot portion; a frame joined to a seat back and turnably supported on the joining unit; a walk-in member turnably supported on the joining unit about a first pivot portion, and having an input portion and an output portion with the first pivot portion located between the input portion and the output portion; a disengagement member turnably supported on the joining unit about a second pivot portion, the disengagement member having one end portion joined to the output portion via a rod, another end portion arranged at a position being at a right angle to the one end portion, and a pressing portion formed on the one end portion; the rod joining the output portion of the walk-in member and the one end portion of the disengagement member; and a tip-up locking member turnably supported on the joining unit about the second pivot portion, the tip-up locking member having one end portion contacting the pressing portion, another end portion formed on the one end portion in a bifurcated shape, and an engagement portion extending from the one end portion and the other end portion toward a front side; a spring suspended between the other end portion of the tip-up locking member and the joining unit, and constantly rotationally biasing the tip-up locking member about the second pivot portion in a counterclockwise direction; a movement hole provided in the joining unit; a stopper member joined to the cushion frame and capable of engaging with and disengaging from the engagement portion of the tip-up locking member, the stopper member moving inside the movement hole in response to turn of the cushion frame about the third pivot portion; and a biasing unit applying a rotational biasing force to the third pivot portion in the counterclockwise direction, wherein a forward tilting of the frame causes a turning of the walk-in member, the turning of the walk-in member causes a turning of the disengagement member, the turning of the disengagement member causes a turning of the tip-up locking member thereby disengaged from the stopper member, and then the cushion frame is tipped up by the rotational biasing force applied by the biasing unit.