A vehicle seat assembly including a lower seat cushion supported by the vehicle and a seat back supported for movement between an upright position and a stowed position. The seat assembly also has a headrest supported for movement relative to the seat back. A locking mechanism engages the headrest to retain the headrest in a raised position when the seat back is in the upright position. The locking mechanism also disengages the headrest for allowing movement of the headrest away from the raised position when the seat back is moved toward the stowed position. The seat assembly also has a biasing mechanism that biases the headrest toward the raised position.