Bohm was known for playing Kaiser Franz Joseph in 1955's Sissi and its two sequels, as well as the serial killer in Michael Powell's Peeping Tom in 1960.
He also played Jacob Grimm in The Wonderful World of the Brothers Grimm in 1962 and Ludwig Beethoven in The Magnificent Rebel.
The following decade, he worked with New German Cinema director Rainer Werner Fassbinder, starring in four of his films.
Bohm turned to activism in later years, founding the charity Humans for Humans after losing a bet on German TV show Wanna Bet?. The charity raises money to help people in Ethiopia.
He received several honours for his charity work, including the Balzan Prize in 2007 and the Essl Social Prize in 2011. He was also handed honorary Ethiopian citizenship in 2003.
Bohm is survived by wife Almaz Teshome and five children from previous marriages.
The actor's parents