Sand Eel or Sandeel is the common name used for a considerable number of species of fish. Most of them are sea fish of the genera Hyperoplus (greater sandeels), Gymnammodytes or Ammodytes. Many species are found off the western coasts of Europe from Spain to Scotland, and in the Mediterranean and Baltic Seas.

The three genera listed above all fall within the family Ammodytidae , the sandlances . Members of these genera found in other oceans are not usually called Sand Eels, and species from other parts of the world that are known as sandeels are usually less closely related. None of the Sand Eels are related to the true eels.

Sandeels are an important food source for diving birds, including puffins and shags. Traditionally they have been little exploited for human food, but increasing fishing of them is thought to be causing problems for some of their natural predators especially the auks which take them in deeper water.