A stowable rear seat, comprising: a seat back unit; and a seat cushion unit, wherein the seat back unit comprising: a tiltable seat back body for erection on a floor surface; a seat back locking mechanism for locking a tilt of the seat back body; and a rocking member provided at a lower end of the seat back body, the rocking member configured for rocking in an anteroposterior direction in cooperation with a tilting operation of the seat back body after unlocking of the seat back locking mechanism; the seat cushion unit comprising: a seat cushion body configured for horizontal placement on the floor surface in front of the seat back body, the seat cushion body being configured to be foldable on a foot floor surface at a lower position than the floor surface; and a seat cushion locking mechanism configured for provision in the floor surface, the seat cushion locking mechanism configured to engage with a back end of the seat cushion body to lock a horizontal state of the seat cushion body on the floor surface, and the rocking member is configured to be detached from the seat cushion locking mechanism when the seat back body is in an upright state, and is configured to be in contact with the seat cushion locking mechanism when the seat back body is in a tilted state to release the lock of the seat cushion locking mechanism. a seat back unit; and a seat cushion unit, wherein the seat back unit comprising: a tiltable seat back body for erection on a floor surface; a seat back locking mechanism for locking a tilt of the seat back body; and a rocking member provided at a lower end of the seat back body, the rocking member configured for rocking in an anteroposterior direction in cooperation with a tilting operation of the seat back body after unlocking of the seat back locking mechanism; a tiltable seat back body for erection on a floor surface; a seat back locking mechanism for locking a tilt of the seat back body; and a rocking member provided at a lower end of the seat back body, the rocking member configured for rocking in an anteroposterior direction in cooperation with a tilting operation of the seat back body after unlocking of the seat back locking mechanism; the seat cushion unit comprising: a seat cushion body configured for horizontal placement on the floor surface in front of the seat back body, the seat cushion body being configured to be foldable on a foot floor surface at a lower position than the floor surface; and a seat cushion locking mechanism configured for provision in the floor surface, the seat cushion locking mechanism configured to engage with a back end of the seat cushion body to lock a horizontal state of the seat cushion body on the floor surface, and a seat cushion body configured for horizontal placement on the floor surface in front of the seat back body, the seat cushion body being configured to be foldable on a foot floor surface at a lower position than the floor surface; and a seat cushion locking mechanism configured for provision in the floor surface, the seat cushion locking mechanism configured to engage with a back end of the seat cushion body to lock a horizontal state of the seat cushion body on the floor surface, and the rocking member is configured to be detached from the seat cushion locking mechanism when the seat back body is in an upright state, and is configured to be in contact with the seat cushion locking mechanism when the seat back body is in a tilted state to release the lock of the seat cushion locking mechanism.