| Zwiefalter Aach | |
| Pushpin Map: | Germany |
| Pushpin Map Caption: | Mouth of the Ziefalter Aach |
| Mouth Coordinates: | 48.2592°N 9.4481°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Germany |
| Subdivision Type2: | State |
| Subdivision Name2: | Baden-Württemberg |
| Length: | 8.9km (05.5miles) |
The Zwiefalter Aach or Zwiefalter Ach is a river in Reutlingen district and Biberach district in Baden-Württemberg, Germany. It is approximately 9 kilometres long and is a tributary of the Danube near Zwiefalten.The river is known for the Wimsener Höhle.[1]