Lancet may refer to:
- lancet (surgery), a medical instrument, similar to a scalpel but with a double-edged blade.
- lancet, a needle used in a lancing device. Used by those with diabetes.
- lancet, an acutely pointed arch in gothic architecture
- 'Lancet', an emergency escape vessel, appearing in the 1960s German TV series Raumpatrouille Orion.
- 'Lancet', an ability from the Final Fantasy videogame series that drains health from opponents.
- lancet window, a tall narrow window with a pointed arch at its top
- The Lancet, a medical journal in the United Kingdom.
- Lancelet (also called Amphioxus), a primitive member of the Phylum Chordata in Subphylum Cephalochordata. It superficially resembles a small fish in the shape of the medical instrument.