One Thousand and One Nights (Arabic: أَلْفُ لَيْلَةٍ وَلَيْلَةٌ, ʾAlf Laylah wa-Laylah) is a collection of Middle Eastern folk tales compiled in Arabic during the Islamic Golden Age. It is often known in English as the Arabian Nights, from the first English-language edition (c. 1706–1721), which rendered the title as The Arabian Nights' Entertainment.

The work was collected over many centuries by various authors, translators, and scholars across West Asia, Central Asia, South Asia, and North Africa. Some tales trace their roots back to ancient and medieval Arabic, Sanskrit, Persian, and Mesopotamian literature. Many tales were originally folk stories from the Abbasid and Mamluk eras, while others, especially the frame story, are probably drawn from the Pahlavi Persian work Hezār Afsān (Persian: هزار افسان, lit. A Thousand Tales), some of which may in turn be translations of older Indian texts.

Common to all the editions of the Nights is the framing device of the story of the ruler Shahryār being narrated the tales by his wife Scheherazade, with one tale told over each night of storytelling. The stories proceed from this original tale; some are framed within other tales, while some are self-contained. Some editions contain only a few hundred stories, while others include 1001 or more. The bulk of the text is in prose, although verse is occasionally used for songs and riddles and to express heightened emotion. Most of the poems are single couplets or quatrains, although some are longer.

Some of the stories commonly associated with the Arabian Nights—particularly "Aladdin's Wonderful Lamp" and "Ali Baba and the Forty Thieves"—were not part of the collection in its original Arabic versions but were added to the collection by Antoine Galland after he heard them from the Syrian Maronite Christian storyteller Hanna Diab on Diab's visit to Paris. Other stories, such as "The Seven Voyages of Sinbad the Sailor", had an independent existence before being added to the collection.