A scalpel, or lancet, or bistoury, is a small and extremely sharp blade used for surgery, anatomical dissection, podiatry, and various types of crafts (called a hobby knife). Scalpels can be single use or reusable. Reusable scalpels may have permanently attached blades that can be sharpened or, more commonly, single-use removable blades.

Surgical scalpels consist of two parts: a blade and a handle. The handles are often reusable, with the blades replaceable. In medical applications, each blade is used only once (sometimes only for a single, small cut).