| Image Coa: | DEU Grinau COA.svg |
| Coordinates: | 53.7783°N 10.5481°W |
| Image Plan: | Grinau in RZ.svg |
| State: | Schleswig-Holstein |
| District: | Herzogtum Lauenburg |
| Amt: | Sandesneben-Nusse |
| Elevation: | 22 |
| Area: | 2.74 |
| Postal Code: | 23847 |
| Area Code: | 04501 |
| Licence: | RZ |
| Gemeindeschlüssel: | 01 0 53 038 |
| Website: | www.grinau.de |
| Mayor: | Birgit Kraus |
Grinau is a municipality in the district of Lauenburg, in Schleswig-Holstein, Germany.