Fate/stay night (フェイト/ステイナイト Feito/sutei naito?) is a Japanese visual novel developed by Type-Moon, which was originally released as an adult game for Windows. A version of Fate/stay night rated for ages 15 and up titled Fate/stay night Réalta Nua (Irish for "new stars"), which features the Japanese voice actors from the anime series, was released for the PlayStation 2 and later for download on Windows as a trilogy covering the three main story lines. Réalta Nua is also ported to the PlayStation Vita. On October 28, 2005, Type-Moon released a sequel to Fate/stay night, titled Fate/hollow ataraxia. Its plot is set half a year after the events of Fate/stay night.

A manga series adaptation by Datto Nishiwaki was serialized in Kadokawa Shoten's Shōnen Ace magazine between the February 2006 and December 2012 issues. In 2007, the manga was licensed for an English-language release in North America by Tokyopop. A 24-episode anime series created by Studio Deen aired in Japan between January 6 and June 16, 2006. Sentai Filmworks has licensed the television series and re-released the series on DVD and for the first time on Blu-ray Disc. A Fate/stay night film was also created by Studio Deen and was released in Japanese theaters on January 23, 2010. Ufotable has announced a new Fate/stay night anime project, set to air in October 2014.

A series of light novels titled Fate/Zero, set as is a prequel to Fate/stay night, were produced from 2006 to 2007. Three fighting games have been released: Fate/unlimited codes for arcades and PlayStation 2, Fate/tiger colosseum and its sequel Fate/tiger colosseum Upper for PSP. A PSP RPG titled Fate/Extra was released on July 22, 2010, and a sequel and companion game, Fate/Extra CCC, was released on March 28, 2013.