Hammelburg was first documented on 18 April 716 as Hamulo Castellum, when Hedan II, Duke of Thuringia, donated the place to Saint Willibrord.

At this time, the fortress (Castellum) was in a favorable location at a ford on the Franconian Saale, and on the intersection of east–west and north–south trade routes.

In the 12th century, the prince-abbots of Fulda built the castle of Saaleck on the heights over the Saale's left bank for Hammelburg's protection, which particularly served for control of the Trimburg established by the Hennebergs.

Fulda answered this by moving closer to the old opponent with the attachment of Hammelburg and to the stronger development of Saaleck Castle.

From this time the Guardian, Monk and Baderturm, a part of the southern city wall and the Schlossweiher survive.

The parish church Johannes in the old castle district the Hammelburger was left to the national organization.

Despite the support of Fulda and Würzburg, Hammelburg converted early to the Lutheran faith and only by force did the city return to Catholicism in 1604.

From this blooming time of the 16th century, came the (1524-1526) city hall, a new building in the Renaissance style, from architect Johannes Schöner, (1529).

The current city hall, built after the fire in the Gothic style, was occupied on 12 December 1859.