Durarara!! (デュラララ!!), shortened to DRRR!! in some official materials, is a Japanese light novel series written by Ryohgo Narita, with illustrations by Suzuhito Yasuda. Durarara!! tells the story of a dullahan working as an underworld courier in Ikebukuro, an internet-based anonymous gang called the Dollars, and the chaos that unfolds around the most dangerous people in Ikebukuro. The series ran for thirteen volumes, published by ASCII Media Works under their Dengeki Bunko imprint. A sequel series, titled Durarara!! SH set two years after the events of the original series, started in 2014.

The Dullahan is a type of legendary creature in Irish folklore. He is depicted as a headless rider on a black horse, or as a coachman, who carries his own head. As it not widely attested in native sources, including no references to it on the extensive website of the Irish Folklore Commission Dúchas.ie, there is doubt as to whether the Dullahan was originally a part of the Irish oral tradition.