Dirk Johnson was born in Germany on an American military base. His father was a doctor and his mother is a German native. He grew up in New York City and graduated from Trinity High School in 1981. 

During the summers he lived with German relatives in Kronach, a picturesque medieval town in Upper Franconia (Bavaria). His relatives spoke no English so he learned German at an early age.

Johnson attended Bowdoin College, where he double-majored in German and history (high honors). He studied at the University of Munich in 1983-84. After graduating in 1985, he worked and studied seven years in Bonn, Germany, receiving a Magister (in political science, philosophy and German) from the University of Bonn, in 1989. At Bonn, he served as both student assistant and research assistant for the political science professor Dr. Hans-Peter Schwarz. He became close friends with political scientist and political commentator Dr. Gerd Langguth, whose book Auf der Suche nach Sicherheit [In Search of Security, 1995] he translated into English. While in Bonn, he was also employed as Office Manager of the Wall Street Journal/Europe.  

He returned to the States in 1992 and worked for two years in New York City before entering a doctoral program at Indiana University, in 1994. He received his Masters from IU in 1996 and his Ph.D. in German Studies in 2000. Subsequently, he taught one year as Lecturer at IU.

In 2001, Johnson joined the faculty of Hampden-Sydney College, in Virginia, as assistant professor of German. 

Johnson has published articles on Nietzsche and Darwin in peer-reviewed journals and has presented his findings at numerous national and international conferences, including at Cambridge University, St. Andrews, the Technical University of Berlin and the Humboldt. His monograph, Nietzsche's Anti-Darwinism, was published by Cambridge University Press in 2010. His piece on Nietzsche's Zarathustra will be forthcoming in the New Cambridge Companion to Nietzsche (Cambridge UP).

Johnson is currently exploring Nietzsche’s perspective on modern science. He believes that Darwin served as a case study that allowed Nietzsche to fashion a more radical and foundational critique of the modern scientific enterprise. 

Aside from his interest in Nietzsche, Johnson has also worked, presented and published on German film. His contribution to a book dedicated to The Lives of Others was published by the University of Kentucky Press in 2014.  

Johnson became a full professor at Hampden-Sydney College in 2014. He lives with his wife and two sons in Charlottesville, Virginia.