The historic university and Hanseatic city conserves an important monumental heritage of Romanesque and Renaissance buildings, as well as numerous timber framed houses.

Helmstedt is situated in a basin between the Elm and Lappwald hill ranges, at the transition area between the northern foothills of the Harz mountains and the North German Plain.

The settlement in the Duchy of Saxony was first mentioned as Helmonstede in a 952 deed issued by the German king Otto I.

In former times also called Helmstädt, the town developed in the vicinity of the Benedictine St. Ludger's Abbey that was founded around 800 by Saint Liudger as a mission station.

During World War I, in 1916–1917, Germany operated a special prisoner-of-war camp for ethnic Polish officers from the Russian Army, with the aim of subjecting them to propaganda and conscripting them into a planned German-controlled Polish army to fight against Russia (Poland was partitioned between Germany, Russia and Austria at the time).