A soft flat balloon neck closure disc formed of non-rigid, soft, flexible, and resilient material for safe use with fluid filled balloons, including water filled balloons that may be thrown at a person. The device is relatively thick and has a flat top surface, a flat bottom surface, and a peripheral outer surface defining its shape. A first small hole and second small hole are each disposed inwardly from first and second segments of the peripheral outer surface in diametrically spaced apart relation and a first and second slit extend outwardly from the holes to the first and second side segments, respectively, and each has a V-shaped entrance. The first side segment is pushed onto the balloon neck such that the neck passes through the first slit and snaps into the first hole, the disc is slid down on the neck, and the neck is wrapped over the top of the disk, pulled inwardly through the second slit to snap into the second hole, and then back under the disc and upwardly through the first slit and hole.