A seat-belt apparatus of the kind which is arranged to be mounted in a vehicle for automatically moving a seat-belt of the apparatus into, and away from, an operative position across a vehicle seat. A seat-belt retraction mechanism is coupled to the seat-belt and is mounted on a vehicle door adjacent the said seat. The retraction mechanism includes a locking mechanism for inhibiting withdrawal of the seat-belt from the retraction mechanism, and is provided with means for controlling operation of the locking mechanism having a first state in which operation of the locking mechanism is inhibited and a second state in which operation of the locking mechanism is permitted. The means for controlling operation of the locking mechanism may be arranged to inhibit operation of the locking mechanism at least when the door is being opened and to permit operation of the locking mechanism at least when the vehicle is in motion, and, in these circumstances, the means for controlling operation of the locking mechanism may include means responsive to the position of the door to inhibit operation of the locking mechanism whenever the door is open and to permit operation of the locking mechanism whenever the door is closed.