Fate/stay night: Unlimited Blade Works is an anime television series produced by Ufotable. It is based on the visual novel Fate/stay night produced by Type-Moon. The narrative is primarily based on the Unlimited Blade Works storyline in the visual novel, and follows Shirou Emiya, a high school student and amateur magus living in Fuyuki City, Japan. Shirou is unexpectedly brought into the Fifth Holy Grail War, a secret magical tournament in which seven participants, known as "Masters", and their "Servants", reincarnated personifications of legendary historical heroes, fight in a battle royale for the Holy Grail, an omnipotent magical chalice that can fulfill any wish or desire for its victor. When Shirou and his Servant Saber are forced to team up with Rin Tohsaka, another Master in the Holy Grail War, Shirou finds himself earning the strong dislike of Rin's mysterious Servant Archer, whose motivations are unknown.

The concept for the Unlimited Blade Works anime originated from Ufotable president Hikaru Kondo, who wanted to create a new anime adaptation based on the Fate/stay night visual novel. Although initially many staff members were in disagreement over how to properly adapt the novel due to its three routes, it was eventually decided that the Unlimited Blade Works route would be adapted. In creating the series, Ufotable wanted to further explore the protagonist's conflicts with Archer while also providing new scenes not featured in the original visual novel. The series was first announced in early 2014. Its 26 episodes were divided into two seasons that aired from October 4 to December 27, 2014, and April 4 to June 27, 2015, respectively. It was released Blu-ray and DVD in both Japanese and English speaking territories in 2015.

Unlimited Blade Works was one of the most anticipated anime of the end of 2014, following from the general popularity of the Fate franchise and the success of Ufotable's previous adaptation of Fate/Zero. Upon release, it received highly positive reviews from critics, who directed particular praise towards the writing of Shirou and other characters as well as the visually striking animation. It was a major commercial success in Japan, having multiple top-selling home media releases and being the winner of multiple awards from the magazine Newtype.