A zipper, zip, fly, or zip fastener, formerly known as a clasp locker, is a commonly used device for binding together two edges of fabric or other flexible material. Used in clothing (e.g. jackets and jeans), luggage and other bags, camping gear (e.g. tents and sleeping bags), and many other items, zippers come in a wide range of sizes, shapes, and colors. In 1892, Whitcomb L. Judson, an American inventor from Chicago, patented the original design from which the modern device evolved.

The zipper gets its name from a brand of rubber boots (or galoshes) it was used on in 1923. The galoshes could be fastened with a single zip of the hand, and soon the hookless fasteners came to be called "Zippers".