The Memminger Ach (or seldom Memminger Aach) is a river in Bavaria, Germany.
The Memminger Ach is a tributary of the Iller, part of the Danube river system, and forms an important part of the landscape in the town of Memmingen. The river is long ( including its source river Kressenbach). It flows into the Iller near PleÃÂ.