Watership Down is the first and most successful novel by British author Richard Adams. A heroic fantasy about a small group of rabbits, it was published in the UK by Rex Collings Ltd in 1972. Although the animals in the novel live in their natural environment, they are anthropomorphized, possessing their own culture, language (Lapine), proverbs, poetry, and mythology. Evoking epic themes, the novel recounts the rabbits' odyssey as they escape the destruction of their warren to seek a place in which to establish a new home, encountering perils and temptations along the way.

The novel takes its name from the rabbits' destination, Watership Down, a hill in the north of Hampshire, England, near the area where Adams grew up. The story is based on a collection of tales that Adams told to his young children to pass the time on trips to the countryside.

Though it was initially rejected by thirteen publishers, Watership Down has never been out of print and was the recipient of several prestigious awards. Adapted into an acclaimed classic film and a television series, it is Penguin Books' best-selling novel of all time. In 1996, Adams published Tales from Watership Down, a follow-up collection of 19 short stories about both El-ahrairah and the rabbits of the Watership Down warren.