Pfäffikon (German pronunciation: [ˈpfɛfikɔn]) is a municipality in the canton of Zürich in Switzerland . It is the seat of the district of the same name. It is not to be confused with Pfäffikon SZ on Lake Zurich but in the canton of Schwyz.

In Roman era, along Pfäffikersee there was built 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.