| Image Coa: | DEU Bäk COA.svg |
| Coordinates: | 53.7114°N 10.7825°W |
| Image Plan: | Bäk in RZ.svg |
| State: | Schleswig-Holstein |
| District: | Herzogtum Lauenburg |
| Amt: | Lauenburgische Seen |
| Elevation: | 38 |
| Area: | 4.3 |
| Postal Code: | 23909 |
| Area Code: | 04541 |
| Licence: | RZ |
| Gemeindeschlüssel: | 01 0 53 004 |
| Mayor: | Thomas Teut |
| Party: | CDU |
Bäk is a municipality in the district of Lauenburg, in Schleswig-Holstein, Germany.