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.

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.