Baccano! (バッカーノ! Bakkāno!, Italian for ruckus) is an ongoing light novel series written by Ryohgo Narita and illustrated by Enami Katsumi. It takes place in the same universe as Narita's light novel series Durarara!!, Vamp!, and Etsusa Bridge, and is known for its non-linear presentation, heavy western influences, and the interconnected quality of its large ensemble cast.
Heavily influenced and inspired by western gangster films (such as the 1987 movie The Untouchables), and wanting to write a story with a unique premise and setting, Narita decided to research and write a story incorporating fantasy elements into an American Prohibition era setting and wrote his first full-length novel over the course of two weeks during the spring break between his junior and senior years of college. He submitted the novel – The Rolling Bootlegs – to the 9th Dengeki Novel Prize Competition, and the novel tied for the Gold Prize: one million yen; and a guarantee that the novel would be published by Dengeki Bunko with full illustrations from a hired artist.
Narita had not written the first Baccano! novel with the firm expectation that it would become a series, and many of the characters and elements of later novels, such as the character Czeslaw Meyer, were not conceived until after the first novel was a published success. The Rolling Bootlegs itself was quite different from some of Narita's early drafts of his story, which featured Ennis as a succubus familiar of an evil sorcerer, whom the main characters and various gangs would fight until they could successfully steal her away from him. 
- The majority of the novels are named after western bands.