In medieval times the county of Dillingen was established. The counts of Dillingen ruled from the 10th to the 13th century, then (1258) the territory was turned over to the Prince Bishops of Augsburg, who gained several villages for their clerical state, hence subdividing the region into several patches, which were dissolved in the early 19th century. In 1804 Dillingen and its area became part of the state of Bavaria.
The district was established in 1972 by merging the former district of Dillingen (which had existed since 1804) with the western half of the former district of Wertingen. The city of Dillingen lost its status as a district-free city and became the capital of the newly established district.
|The white lion was part of the arms of the medieval county of Dillingen. The black lion in the middle is taken from the arms of the dissolved district of Wertingen. The fleur-de-lis is from the arms of the city of Dillingen.|