Moray eels, or Muraenidae (/ˈmɒreɪ, məˈreɪ/), are a family of eels whose members are found worldwide. There are approximately 200 species in 15 genera which are almost exclusively marine, but several species are regularly seen in brackish water, and a few are found in fresh water.

The English name, from the early 17th century, derives from the Portuguese moréia, which itself derives from the Latin mūrēna, in turn from the Greek muraina, a kind of eel.