A sash is a cloth belt designed to hold a robe together, usually tied about the waist. The Japanese equivalent of a sash, called an obi, is used for holding a kimono or yukata together. Sashes are traditionally part of formal military attire, and some decorations such as the Legion d'honneur are worn with a special sash. In South and Latin America, the president's authority is indicated by a special Presidential sash. Decorative sashes may pass from the shoulder to the hip rather than around the waist.

In many Un*x-type computer operating systems, sash is a statically linked shell which includes many built-in system commands. In case of a system failure, sash can be used during recovery without important libraries in place.

In architecture, a sash is the framing in which panes of glass are set in a glazed window or door, including the narrow bars between the panes.