| Letnica | |
|---|---|
  Location of the mouth in Poland | |
| Location | |
| Country | Poland |
| Voivodeship | Greater Poland |
| Physical characteristics | |
| Source | |
| • location | Zdrój, Greater Poland Voivodeship |
| • coordinates | 52°13′52″N 16°17′34″E / 52.23111°N 16.29278°E |
| Mouth | |
• location | Obra |
• coordinates | 52°06′50″N 16°25′26″E / 52.11389°N 16.42389°E |
Letnica is a river of Poland, a tributary of the Obra. The river flows through the town of Grodzisk Wielkopolski.