Kellmünz gets attention among the many settlements in the Iller valley due to its uncommon name, which points to a pre-Germanic past.

The legionaries renamed an initially Celtic settlement to Caelius Mons, probably referring to the Caelian Hill in Rome.

After the fall of the Limes in the face of Alemannic pressure, the Romans changed their strategy to protect the Alpine foothills.

At the place, where the church stands today, was an equally large hall with an apse and a portico.

Near the end of the war, on 25 April 1945, the bridge over the Iller was destroyed by the Wehrmacht, in order to prevent the allied troops the passing to Bavaria.