A vehicular seat is provided with which compactness can be achieved in a housed state where a seat main body is housed. A vehicular seat is a seat configured to be housed in a housing recess formed in a vehicle body floor. The vehicular seat includes: right and left rail devices fixed on the vehicle body floor and supporting a seat main body to be movable in the front to back direction; and a reclining device pivotably connecting the seat main body to a support base constructed on the right and left rail devices. The reclining device is arranged at a height position overlapping upper rails in the up and down direction, and is arranged outside the upper rails in a seat width direction.