»Scardigna« was first mentioned in documents in 804; in the course of the 9th and 10th centuries, Schärding became the centre of the county of Vornbach-Neuburg. The Counts of Andech followed in 1160 and the Bavarian Wittelsbachs in 1248.
In addition to its economic importance as a trading town on the river Inn, there was soon a great deal of early political activity as well. The Bavarian dukes, above all Ludwig the Bearded (in the 15th century), built Schärding into a strong fortification.
The town suffered severe damage through devastating fires (in 1724 and 1779), and French occupation (1809). After the Napoleonic Wars in 1816, the Innviertel region was again Austrian.