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, Central and South Asia, and North Africa. Some tales themselves trace their roots back to ancient and medieval Arabic, Persian, Indian, Greek, Jewish and Turkish folklore and literature. In particular, many tales were originally folk stories from the Abbasid and Mamluk eras, while others, especially the frame story, are most probably drawn from the Pahlavi Persian work Hezār Afsān (Persian: هزار افسان‎, lit. A Thousand Tales), which in turn relied partly on Indian elements.

What is common throughout all the editions of the Nights is the initial frame story of the ruler Shahryār and his wife Scheherazade and the framing device incorporated throughout the tales themselves. The stories proceed from this original tale; some are framed within other tales, while others are self-contained. Some editions contain only a few hundred nights, while others include 1,001 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 Nights, in particular "Aladdin's Wonderful Lamp", "Ali Baba and the Forty Thieves", and "The Seven Voyages of Sinbad the Sailor", were not part of The Nights in its original Arabic versions but were added to the collection by Antoine Galland and other European translators.