Irgenhausen is a village (Aussenwacht) of the municipality of Pfäffikon in the canton of Zurich in Switzerland.

Irgenhausen belongs politically to the municipality of Pfäffikon.

In Roman era, along Pfäffikersee there was a Roman road from the vicus Centum Prata (Kempraten) on Obersee–Lake Zürich via Vitudurum (Oberwinterthur) to Tasgetium (Eschenz) to the Rhine.

To secure this important transport route, the Irgenhausen Castrum was built.

The native name of the fort is unknown, thus Irgenhausen was mentioned in 811 AD as Camputuna sive Irincheshusa.