Irschen is a municipality in the district of Spittal an der Drau in the Austrian state of Carinthia.

It is situated on the northern slope of the Upper Drava Valley, near the B 100 Drautal Straße highway and the Drautalbahn railway line.

A settlement area since the Early Iron Age (Hallstatt Culture), Irschen may be identical to the Idunum polis in the former Celtic kingdom of Noricum, as mentioned in Ptolemy's Geographia.

In Roman times a mansio laid on the road leading over the Gailbergsattel mountain pass to Italia.

It was recently revealed that the English actress Billie Piper has a home in this region.