The town developed in the 7th century as an Alemannic settlement in the Virgunna forest next to the Franconian-Swabian border.

In 764 the Frankish noble Hariolf, Bishop of Langres, founded a Benedictine monastery, Ellwangen Abbey, on a hill next to the settlement.

From 870 to 873 the Byzantine Greek "Apostle of the Slavs" Saint Methodius was imprisoned in Ellwangen, after he had been arrested by Ermanrich, bishop of Passau.

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).

[7] In April and May 2018, two police raids at a migrant shelter in the town led to national and international media attention and a public debate about legal deportations.

Ellwangen is served by the Upper Jagst Railway which is operated by both GoAhead and Deutsche Bahn.

A Stadtbus only stops if requested by the passengers and was established for older residents and the population surrounding the historic center of the town.

Sights of the city are the medieval town centre with its churches, notably Ellwangen Basilica.