Nagaru Tanigawa is a Japanese author best known as the creator of the Haruhi Suzumiya series, a multimedia franchise that began as a light novel and expanded into multiple anime adaptations, manga series, and films. He was born on December 19, 1970 in Nishinomiya, Hyogo Prefecture, Japan, and is a graduate of the law school at Kwansei Gakuin University. Before his career as a writer, Tanigawa worked as a manager at a women's clothing store. His official debut came in March 2003 with the publication of the novel Dengeki Aegis 5. Shortly thereafter, on June 7, 2003, he won the eighth annual Sneaker Grand Prize for the first volume of his most famous work, The Melancholy of Haruhi Suzumiya, which was published on the same day as his novel Escape from the School.

As an original creator, Tanigawa is most significantly associated with the Haruhi Suzumiya light novel series, which he writes, with illustrations provided by Noizi Ito. The series is published by Kadokawa Shoten under their Kadokawa Sneaker Bunko imprint. The first novel, The Melancholy of Haruhi Suzumiya, was released in 2003, and the series has since grown to include thirteen volumes, the most recent being The Intuition of Haruhi Suzumiya published in 2020 after a nine-year hiatus. The immense popularity of the light novels led to their adaptation into a celebrated anime television series, also titled The Melancholy of Haruhi Suzumiya, produced by Kyoto Animation and first broadcast in 2006, with a rebroadcast that included new episodes in 2009. The story was continued in the animated film The Disappearance of Haruhi Suzumiya, released in 2010.

Beyond the core series, the Haruhi Suzumiya universe spawned several spin-off manga and anime projects for which Tanigawa is credited as the original author. The official parody four-panel manga The Melancholy of Suzumiya Haruhi-chan by Puyo was adapted into an original net animation series of the same name. Similarly, the manga Nyorōn Churuya-san by Eretto, which features a super-deformed version of the character Tsuruya obsessed with smoked cheese, was also adapted into an original net animation series titled Nyoron! Churuya-san. Both of these short-form anime series were released in 2009. Tanigawa also contributed directly to the scripts for several episodes of the 2006 and 2009 anime television series, including Someday in the Rain and The Sigh of Haruhi Suzumiya I, and provided the lyrics for the theme song of The Disappearance of Haruhi Suzumiya.

In addition to the Haruhi Suzumiya franchise, Tanigawa has authored several other light novel series, including Escape from the School, which was published under the Dengeki Bunko imprint, The Guardian of My World, and the two-volume series Dengeki Aegis 5. He also wrote the manga Amnesia Labyrinth, which was serialized in Dengeki Bunko Magazine with art by Natsumi Kohane. His other original works include the short story Round-Trip, published in a Sneaker Bunko 25th anniversary anthology.

Tanigawa's work, particularly the Haruhi Suzumiya series, is noted for its blend of science fiction concepts, mystery, and romantic comedy elements. The series is known for its postmodern narrative structure, which includes metafictional commentary and an exploration of genre tropes. The central premise, in which a high school girl unknowingly possesses the power to alter reality, creating a narrative watched over by aliens, time travelers, and espers, became highly influential in the light novel and anime industries. Tanigawa has cited a range of influences on his writing, including the science fiction of Isaac Asimov, the mystery novels of Ellery Queen and S. S. Van Dine, the works of Japanese authors Hideyuki Kikuchi and Baku Yumemakura, and the anime films of director Mamoru Oshii, particularly Urusei Yatsura 2: Beautiful Dreamer.