Abstract: A seat belt buckle guard comprises a one-piece, molded plastic, box-like enclosure having one open end and an opposite end wall with a slot. The seat belt buckle fits through the open end into the enclosure with its latch plate receiving slot aligned with the slot in the housing. The latch plate on one belt half can be inserted through the housing slot to make with the buckle. Formed in the top wall and the end wall is an opening for gaining access to the buckle release button. In one arrangement, the opening is a narrow slot through which a flat object, such as a key, can be inserted to operate the buckle's release button. In accordance with an alternative embodiment, the opening is a circular aperture of a size permitting one's finger to be inserted to operate the release button. The opening is surrounded by a tubular stub or neck threaded on its exterior to receive a child-resistant safety cap of the type commonly used on medicine bottles.