Abstract: A locking device for a buckle including a male member and a female member having coupling apertures formed in opposing sides. The male member includes a pair of resilient arms having coupling tabs for cooperating with the coupling apertures of the female member. The female member has guide means for receiving a guide member on the male member during insertion of the male member into the female member. The female member is provided with a locking device in the form of a locking member slidable in a slot to a position where it prevents depression of one of the resilient arms to release the coupling tabs from the coupling apertures. The lock is released by sliding the locking member along the slot in a direction away from the resilient arm. Accidental or unauthorised release of the buckle can therefore be prevented by providing the locking device on a side of the female member next to the wearer.