Born in Wuppertal, Medick studied history, philosophy, English and political science at the universities of Cologne, Heidelberg and Erlangen from 1959 to 1966.
After graduating with a master's degree, he was a research assistant at the University of Erlangen from 1967 to 1973, where he also received his doctorate under Kurt Kluxen in 1971.
From 1973 to 2004, he worked as a research assistant at the Göttingen Max Planck Institute for the Study of Religious and Ethnic Diversity.
His research focuses on the experiences and representations of violence during the Thirty Years' War, concepts of person and self in their cultural expressions and practices, methodological approaches of microhistory and historical anthropology.
Since the 1980s, Medick has been one of the protagonists of microhistory or Alltagsgeschichte, which already anticipated many of the methodological innovations of the cultural turn of historical studies (Neue Kulturgeschichte [de]) in the 1990s.