| Glonn | |
| Mouth Location: | at Allershausen into the Amper |
| Mouth Coordinates: | 48.4331°N 11.6039°W |
| Subdivision Type1: | Country |
| Length: | 51.7km (32.1miles) |
| Source1 Elevation: | about |
| Mouth Elevation: | about |
| Basin Size: | 405km2 |
The Glonn is a river of Upper Bavaria, Bavaria, Germany.
The Glonn is long. It rises southeast of Mittelstetten in the district of Fürstenfeldbruck. It is the main tributary of the Amper; at Allershausen near Freising it discharges from the left into the Amper.
The Glonn flows through an agriculturally used area in the triangle between Augsburg, Freising and Dachau. Larger places in its course are Odelzhausen, Erdweg, Markt Indersdorf, Weichs, Petershausen and Hohenkammer.