Sky du Mont (born Cayetano Neven DuMont, often spelled Sky Dumont) was born on May 20, 1947, in Buenos Aires, Argentina, to a German father and a British mother. He comes from the Neven DuMont publishing family, which had fled to South America in the 1930s to escape the Nazis. In 1952, the family returned to Europe, and du Mont grew up in Munich, Switzerland, and London. 

From 1969 to 1971, he attended an acting school in Munich and passed his final examination with the State Theatre Association. He then appeared in theater productions at the Munich Residenztheater and the Berlin State Theatre. At the same time, he began taking small film roles, such as in "Alter Kahn und junge Liebe" (1973) and "Das Schweigen im Walde" (1976). He had a more significant part in Wolfgang Liebeneiner’s "Götz von Berlichingen mit der eisernen Hand" (1978) as Hans von Selbitz, a companion of Götz von Berlichingen. Du Mont also appeared frequently on television, with roles ranging from crime series like "Der Kommissar" (1974) and "Whodunnit" (1977) to literary adaptations such as "Die Kameliendame" (1978). His imposing presence and refined demeanor often led to casting as aristocrats, doctors, or high-ranking military officers.

In the late 1970s and early 1980s, du Mont worked mainly in international films. He played a Nazi who fled to Brazil in the thriller "The Boys from Brazil" (US, 1978), appeared alongside Lee Marvin, Maximilian Schell, and Horst Buchholz in the spy film "Avalanche Express" (US, 1978), and portrayed Italian Prince Amedeo of Aosta in the adventure film "Omar Mukhtar – Lion of the Desert" (UK, 1980). In the German co-production "Night Crossing" (UK/US/DE, 1981), he played a Stasi agent.

After his role as a supposed jet-set millionaire in the comedy "Otto – Der Film" (1985), du Mont focused almost entirely on television from the mid-1980s onward. He made guest appearances in many popular series, including "Derrick," "Der Alte," "Ein Fall für zwei," "SOKO München," and "Unser Charly." In the American miniseries "War and Remembrance" (1988/89), he portrayed the Hitler assassin Claus Schenk von Stauffenberg. He also held recurring roles as a wealthy Italian admirer in the US soap opera "General Hospital" (1989) and as a clinic director in the German series "Forsthaus Falkenau" (1999/2000).

Du Mont returned to cinema with a small but memorable role in Stanley Kubrick’s "Eyes Wide Shut" (US/UK, 1999), playing a charming Hungarian businessman flirting with Nicole Kidman at a high-society party. The following year, he joined the prominent cast of Romuald Karmakar’s "Manila" (2000). One of his biggest successes in Germany came with the Western parody "Der Schuh des Manitu" ("Manitou's Shoe," 2001), in which he played a clumsy villain and showcased his comedic talent. He continued in comedy roles as Hape Kerkeling’s father in "Samba in Mettmann" (2004) and as a medieval duke in the "Star Trek" parody "(T)Raumschiff Surprise – Periode 1" (2004). 

Despite the success of these films, du Mont returned primarily to television in the following years. He starred in the Austrian comedy series "Arme Millionäre" (2005–2006), appeared in several films of the "Tatort" crime series, and played the lead role of investigator Christian Graf Landsburg in the crime film "Prinz und Paparazzi" (2005), based on his own novel. In 2005/2006, he also appeared with his fourth wife, Mirja du Mont, as part of the regular cast of the game show "Typisch Frau – Typisch Mann." 

Other notable TV films include Wolf Gremm’s family drama "Sommerlicht" (2011), the comedy "Der Heiratsschwindler und seine Frau" (2012) with Armin Rohde, Detlev Buck, and Nicolette Krebitz, and Su Turhan’s fairy-tale adaptation "Die drei Federn" (2014). He received particular praise for Uwe Janson’s satirical TV film "Die Schlikkerfrauen" (2014), which humorously depicted the collapse of the Schlecker drugstore chain, in which du Mont played the fictional company owner. 

On the big screen, he appeared only in supporting roles in "Otto’s Eleven" (2010) and the children's film "Fünf Freunde 3" (2014), both times as a suave villain. He returned to a leading cinematic role in Michael Herbig’s comedy "Bullyparade: Der Film," released in August 2017, playing a general.

He did not appear on the big screen again until 2025, first in a small role in the film debut "Der Saft des Bösen" by Berlin drag icon Nina Queer, followed by a role in the sequel to the cult film "Der Schuh des Manitu," "Das Kanu des Manitu" ("The Canoe of Manitou"), in which he once again played the villain Santa. Even before filming began, du Mont announced that this would be his final on-screen role, as he planned to focus on other professional pursuits. 

Away from acting, Sky du Mont has long been active as a narrator and voice artist in audiobooks and radio plays. Between 2003 and 2016, he also published a children’s book, three crime novels, and three non-fiction works. In 2025, he appeared in Hanover as the narrator in a stage production of "The Rocky Horror Picture Show."