Allison (アリソン, Arison) is a Japanese light novel series written by Keiichi Sigsawa, with illustrations by Kouhaku Kuroboshi.

Allison is an adventure series set in a world containing one continent (extending roughly from the Equator to 60 degrees North latitude) which is divided down the center by a towering mountain range and a huge river.

At the beginning of the first novel, Allison, a pilot in the Roxche Air Force, has come to visit her childhood friend Wilhelm ("Wil" for short), who has remained at school over his summer break to continue his studies.

Years earlier, Allison, Wil, and Fiona are each shocked to find themselves the recipients of a ticket for the Transcontinental Limited Express, courtesy of Benedict.

The luxury train, on only its fourth trip, is set to take them on a multi-day journey from Roxche to Sou Beil, across the only recently completed bridge over the Lutoni River.

However, the quartet's peaceful ride in the lap of luxury is brought to an abrupt end when the train's conductors and passenger attendants are murdered, with the killer still among them.

Diverting to a nearby Sou Beil army base, the train leaves most of its guests (save for the targeted steel magnate Mr. Terror) in the hands of the soldiers there.

Back in the present, Lillia welcomes both her mother's boyfriend, a Major in the Sou Beil Army, and her childhood friend Treize into her home.

But unbeknownst to her, the two men harbor their own secrets... A sound novel, with card game attributes, based on the series was released on December 7, 2006 in limited and regular editions by MediaWorks playable on the Nintendo DS.

Allison was the first game produced under DS Dengeki Bunko, and the only others include Baccano!, Inukami!, and Iriya no Sora, UFO no Natsu.