| Image Coa: | DEU Quarnstedt COA.svg |
| Coordinates: | 53.95°N 56°W |
| Image Plan: | Quarnstedt in IZ.png |
| State: | Schleswig-Holstein |
| District: | Steinburg |
| Amt: | Kellinghusen |
| Elevation: | 4 |
| Area: | 10.59 |
| Postal Code: | 25563 |
| Area Code: | 04822 |
| Licence: | IZ |
| Gemeindeschlüssel: | 01 0 61 088 |
| Website: | www.kellinghusen.de |
| Mayor: | Adolf Humfeldt |
Quarnstedt is a municipality in the district of Steinburg, in Schleswig-Holstein, Germany.