The Trave river flows through the district before entering the city of Lübeck. In the southernmost portion of Stormarn are the eastern suburbs of the Hamburg metropolitan area.
The name Stormarn may be derived from "storm", hence meaning "stormy land". In medieval times the name was applied to a larger area, whereof the present-day district is only the eastern half. The heraldic animal of Stormarn is the swan.
Towns in Stormarn: Bad Oldesloe, Bargteheide, Reinfeld, Reinbek, Ahrensburg, Glinde.