An eel buck or eel basket is a type of fish trap that was prevalent in the River Thames in England up to the 20th century. It was used particularly to catch eels, which were a staple part of the London diet.
Eel bucks were baskets made of willow wood, and were often strung together in a fishing weir. Construction of such weirs was outlawed under the terms of Magna Carta:
However the practice continued unabated, often with adverse effects on navigation.
Several islands in the River Thames reflect the presence of bucks at those points; for example, Buck Ait and Handbuck Eyot.
A surviving eel buck may be seen on the River Test at 51°7′48″N 1°29′5″W / 51.13000°N 1.48472°W.