| Lengwitz | |
| Mouth Location: | Ilm |
| Mouth Coordinates: | 50.6433°N 10.8551°W |
| Subdivision Type1: | Country |
| Subdivision Type2: | States |
Lengwitz is a river of Thuringia, Germany. At its confluence with the Freibach and the Taubach near Stützerbach, the Ilm is formed.