Irdning is a former municipality in the district of Liezen, in the Austrian state of Styria. It lies in the Enns Valley region of central Austria, within the larger Liezen district that covers much of northwestern Styria.
Since the 2015 Styria municipal structural reform, Irdning is no longer a separate municipality. It was merged into the newly formed municipality of Irdning-Donnersbachtal, which combines the area with the neighbouring community of Donnersbachwald. The name Irdning is retained in the combined municipality's name.
As a result of the reform, Irdning now exists as a cadastral community and settlement within Irdning-Donnersbachtal rather than as an independent administrative unit. Its administrative functions are handled by the merged municipality.