| Mouth location | Iller |
|---|---|
| Mouth coordinates | 47.9622°N 10.0847°E |
| Country | Germany |
| State | Baden-Württemberg |
| Length | 39.6 km (24.6 mi) |
Aitrach is a river of Baden-Württemberg, Germany. It is formed at the confluence of the Wurzacher Ach and the Eschach near Leutkirch im Allgäu. It is a left tributary of the Iller, which it joins near the village Aitrach. Including the Wurzacher Ach, it is 39.6 km long.