| Rethwisch | |
| Image Coa: | DEU Rethwisch (Steinburg) COA.svg |
| Coordinates: | 53.8667°N 9.5917°W |
| Image Plan: | Rethwisch in IZ.png |
| State: | Schleswig-Holstein |
| District: | Steinburg |
| Amt: | Krempermarsch |
| Elevation: | 5 |
| Area: | 9.83 |
| Postal Code: | 25566 |
| Area Code: | 04828 |
| Licence: | IZ |
| Gemeindeschlüssel: | 01 0 61 092 |
| Website: | www.amt- krempermarsch.de |
| Mayor: | Michael Nagel |
Rethwisch is a municipality in the district of Steinburg, in Schleswig-Holstein, Germany.