A shaker is a device used in chemistry and biology laboratories to stir liquids.

A typical shaker has a table board that oscillates horizontally, powered by an electric motor. The liquids to be stirred are held in beakers, jars, or Erlenmeyer flasks that are placed over the table; or, sometimes, in test tubes or vials that are nested into holes in the plate. Orbital shakers also exist, that shake the vessel in a circular fashion.

Shakers have largely been replaced by magnetic stirrers for many purposes, but are still favoured for some situations, such as those involving large volumes.