Several groups of long, thin fishes (not closely related) are known as eels:
- True eels belong to the order Anguilliformes.
- Spiny eels are deep sea fishes belong to the family Notacanthidae.
- The Electric eel, Electrophorus electricus, belongs to the knifefish family Gymnotidae.
- Swamp eels belong to the order Synbranchiformes.
- Cusk eels belong to the family Ophidiidae.
- Bobtail snipe eels belong to the family Cyematidae.
Eel may also refer to:
- Several rivers named Eel River.
- The Eel, a 1997 film directed by Shohei Imamura.
- USS Eel (SS-354), a projected but not completed United States Navy submarine.