| Joachim Frederick | |
| Succession: | Elector of Brandenburg |
| Reign: | 8 January 1598 – 18 July 1608 |
| Predecessor: | John George |
| Successor: | John Sigismund |
| House: | Hohenzollern |
| Father: | John George, Elector of Brandenburg |
| Mother: | Sophie of Legnica |
| Spouse: | Catherine of Brandenburg-Küstrin Eleanor of Prussia |
| Issue: | John Sigismund, Elector of Brandenburg Anne Catherine, Queen of Denmark and Norway Johann Georg of Brandenburg August of Brandenburg Albert Frederick of Brandenburg Joachim von Brandenburg Ernest of Brandenburg Barbara Sophie, Duchess of Württemberg Christian William of Brandenburg Marie Eleonore, Countess Palatine of Simmern-Kaiserslautern |
| Birth Place: | Cölln, Margraviate of Brandenburg, Holy Roman Empire |
| Death Place: | Cöpenick, Margraviate of Brandenburg, Holy Roman Empire |
| Burial Place: | Berlin Cathedral |
| Religion: | Lutheran |
Joachim Frederick (27 January 1546 – 18 July 1608), of the House of Hohenzollern, was Prince-elector of the Margraviate of Brandenburg from 1598 until his death.
Joachim Frederick was born in Cölln to John George, Elector of Brandenburg, and Sophie of Legnica. He served as administrator of the Archbishopric of Magdeburg from 1566 to 1598, then succeeded his father as Elector of Brandenburg in 1598. Joachim Frederick was succeeded at his death by his son John Sigismund. Joachim Frederick's first marriage on 7 March 1570 was to Catherine of Brandenburg-Küstrin, daughter of John, Margrave of Brandenburg-Küstrin, and Catherine of Brunswick-Wolfenbüttel. Joachim Frederick's second marriage, on 23 October 1603, was to Eleanor of Prussia, born 21 August 1583, daughter of Albert Frederick and Marie Eleonore of Cleves. He became regent of the Duchy of Prussia in 1605.His titles also included "duke (Dux) of Stettin, Pomerania, Cassubia, Vandalorum and Crossen", according to the terms of the Treaty of Grimnitz, although the Pomeranian titles were only nominal.
Joachim Frederick and Catherine of Brandenburg-Küstrin had these children:
Joachim Frederick and Eleanor of Prussia had only one child:
Joachim-Friedrich Strasse in Berlin is named after him. [1]