In medieval times the name Stormarn was applied to a larger area, of which the present-day district is only the eastern half.

When Schleswig-Holstein became a province of Prussia in 1867, the Prussian administration established the district of Stormarn, with Wandsbek as its capital.

In 1970 Stormarn again lost a substantial portion of its territory, when the city of Norderstedt was founded in order to become a part of the Segeberg district.

In the southernmost portion of Stormarn there are the eastern suburbs of the Hamburg metropolitan area.

The coat of arms displays a white swan, with a crown around its neck, on red ground.