| Type: | Stadt |
| Image Coa: | Wappen_Ketzin-Havel.png |
| Coordinates: | 52.4697°N 12.845°W |
| Image Plan: | Ketzin-Havel in HVL.png |
| State: | Brandenburg |
| District: | Havelland |
| Elevation: | 32 |
| Area: | 92.79 |
| Postal Code: | 14669 |
| Area Code: | 033233 |
| Licence: | HVL |
| Gemeindeschlüssel: | 12 0 63 148 |
| Website: | www.ketzin.de |
| Mayor: | Katrin Mußhoff[1] |
| Leader Term: | 2022 - 30 |
| Party: | SPD |
Ketzin (pronounced as /de/, official name: Ketzin/Havel) is a town in the Havelland district, in Brandenburg, Germany. It is situated on the river Havel, 17 km northwest of Potsdam, and 40 km west of Berlin.
The town counts 6 Ortsteile (civil parishes): Etzin, Falkenrehde, Knoblauch, Paretz, Tremmen and Zachow.
The Ketzin Cable Ferry, a vehicular cable ferry, crosses the Havel between Ketzin and Schmergow.