Justus von Dohnányi, born December 2, 1960, as the son of conductor Christoph von Dohnányi, took actor"s training at Hochschule für darstellende Künste in Hamburg. From 1985 on, he performed at Frankfurt's Schauspielhaus and became a cast member of Hamburg's Thalia Theater in 1998. From 1993 on, von Dohnányi also appeared in numerous TV productions. He made his movie debut in 1999 in the US remake of "Jakob der Lügner" ("Jakob the Liar").

Since then, he most often appeared in ambivalent parts as a person of authority or as a careerist. Dohnányi starred as Captain Nikoli in the James Bond film "The World is not enough" (1999), as a brutal prison officer in "Das Experiment" ("The Experiment", 2001), a role that won him the German film award as "Best supporting actor", as a manager in the thriller "Blueprint" (2003), as a Nazi general in "Der Untergang" ("Downfall", 2004), or as a the head of a Nazi district in "Napola" ("Before the Fall", 2004). In 2007, Justus von Dohnányi made his debut as a director with the comedy "Bis zum Ellenbogen". But Dohnányi not only directed and produced the film, but also wrote the screen play and played a key supporting role.

Dohnanyi returned to acting in the following years, often proving his knack for portraying unsavoury characters, including a turn as an aggressive mobster in "Hardcover" or as a scheming fortune hunter in "Die Buddenbrooks". In television, he appeared as a cook in "Es liegt mir auf der Zunge" and as the first husband of Heike Makatsch's character in "Dr. Hope – Eine Frau gibt nicht auf". His next big screen role was the part of actor Veit Harlan in Oskar Roehler's controversial "Jud Süss – Film ohne Gewissen". In 2010, he won the German Film Award for Best Supporting Actor for his performance as an endearingly delusional singer  in the comedy "Männerherzen". The same year, he joined the ensemble of Dani Levy's "Das Leben ist zu lang" (2010), and went on to play a conservative businessman in the historical sports drama "Der ganz große Traum" (2011).  In the sequel "Männerherzen... und die ganz ganz große Liebe", Dohnanyi reprised his award-winning role.

He then played a mean zoo director hunting for a cuddly snow creature in the childrens' film "Yoko". In "Ruhm" ("Glory: A tale of mistaken identities", 2012), an adaptation of Daniel Kehlmann's eponymous novel, Dohnányi appears as an engineer who starts receiving phone calls from total strangers on his new cell phone.