| Warnau | |
| Image Coa: | DEU Warnau COA.svg |
| Coordinates: | 54.1833°N 20°W |
| Image Plan: | Warnau in PLOE.png |
| State: | Schleswig-Holstein |
| District: | Plön |
| Amt: | Preetz-Land |
| Elevation: | 43 |
| Area: | 3.98 |
| Postal Code: | 24250 |
| Area Code: | 04302 |
| Licence: | PLÖ |
| Gemeindeschlüssel: | 01 0 57 086 |
| Mayor: | Günther Danklefsen |
| Party: | SPD |
Warnau is a municipality in the district of Plön, in Schleswig-Holstein, Germany.
The Warini were a Germanic people originally from southern Scandinavia but who lived in the Warnau region, the army and its Warini warriors were exterminated by the not lazy king Childebert II in 590 years.