Joachim Mörlin April 5, 1514, Wittenberg, Electorate of Saxony – May 29, 1571, Königsberg, Duchy of Prussia (later Kaliningrad in the Soviet Union / Russian Federation after World War II - 1945) was an Evangelical Lutheran theologian and an important figure in the controversies following Martin Luther's (1483-1546) death.
He was the older brother of Maximilian Mörlin, another Lutheran theologian and Reformer.