Horst Buchholz was born in Berlin, the son of Maria Hasenkamp. He never knew his biological father, but took the surname of his stepfather Hugo Buchholz, a shoemaker, whom his mother married in 1938. His half-sister Heidi, born in 1941, gave him the nickname “Hotte”, which he kept for the rest of his life. During World War II he was evacuated to Silesia and at the end of the war found himself in a foster home in Czechoslovakia. He returned to Berlin as soon as he could. He barely finished his schooling before seeking theater work, first appearing on stage in 1949. He soon left his childhood home in East Berlin to work in West Berlin. He established himself in the theater, notably the Schiller Theater, and also on radio. Able to speak several languages, Buchholz expanded into film work by doing foreign-language voice dubbing. In 1951 he started getting small uncredited on-screen parts. He had a marginally larger role in Marianne de ma jeunesse (1954), directed by Julien Duvivier, then won a Best Actor award at Cannes for his part as Mischa Bjelkin in Helmut Käutner’s Himmel ohne Sterne (1955). His youthful good looks next brought him a part in Die Halbstarken (1956), which made him a teen favorite in Germany; an English-dubbed version was released in the US as Teenage Wolfpack, with Buchholz billed as “Henry Bookholt” and promoted as a new James Dean. Full-fledged stardom resulted from Bekenntnisse des Hochstaplers Felix Krull (de) (1957), in which he played the lead; it was directed by Kurt Hoffmann and based on the novel by Thomas Mann. In 1958 Buchholz married French actress Myriam Bru. They had two children.

Buchholz began appearing in English-language films in 1959, when he co-starred in the British production Tiger Bay with Hayley Mills. He followed that with The Magnificent Seven (1960), the romantic drama Fanny (1961) with Leslie Caron and Maurice Chevalier, and the Berlin-set comedy One, Two, Three (1961), directed by Billy Wilder. Though filmed in Mexico, France and Germany respectively, these were Hollywood productions and Buchholz had begun a period of residence in Los Angeles. He proved to be popular with American audiences, but several missed opportunities thwarted the upward trajectory of his career and it began to stall. Filming schedule conflicts prevented him from accepting the offered roles of Tony in West Side Story (1961) and Sherif Ali in Lawrence of Arabia (1962). Later, on the advice of his agent, like many others who were asked he turned down the starring role in A Fistful of Dollars (1964). A versatile actor, Buchholz appeared in comedies, horror films, wartime dramas and other genres, but his best work was mostly behind him by the mid-1960s. The quality of the films in which he appeared diminished, with poorly regarded made-for-television films and episodic television making up the majority of his appearances during the 1970s. One exception was Le Sauveur (1971), directed by French film critic Michel Mardore. In a few of his late-career films he was again given meatier roles in more substantial fare, starring in the bleak And the Violins Stopped Playing (1988) and portraying Dr. Lessing in Roberto Benigni’s Oscar-winning Life Is Beautiful (1997). Usually reticent about his private life, in a 2000 interview in the German magazine Bunte Buchholz publicly came out, saying “Yes, I also love men. Ultimately, I’m bisexual. … I have always lived my life the way I wanted.” He explained that he and his wife of nearly 42 years had a stable and enduring arrangement, with her life centered in Paris and his in Berlin, the city that he loved. Their son Christopher Buchholz, also an actor and the producer of the feature-length documentary Horst Buchholz…Mein Papa (2005), has publicly acknowledged his father’s bisexuality. Buchholz died unexpectedly at the age of sixty-nine in the Berlin Charité from pneumonia that developed after an operation for a hip fracture. Berlin was the city to which his loyalty was constant, and he was buried there in the Friedhof Heerstraße.