Harry Hornig was born October 22, 1930, in Gelsenkirchen. As the son of a mine worker who had died rather early, Hornig also started an apprenticeship as a mine worker after finishing school. At the same time, he also developed an interest for politics and joined the Communist party. After his relocation to East Germany in 1949, he finished his high school exam in Jena and started to study philosophy, German studies, and film studies at Jena's Friedrich Schiller-Universität in 1950.

In 1954, after his graduation from university, he took a job at DEFA-Studio für Wochenschau und Dokumentarfilme and initially worked as an assistant dramaturg, later as a dramaturg and contributing editor. He wrote screenplays and repeatedly collaborated with director Joachim Hadaschik. They, for instance, finished the film "Unsere Freundschaft" (1956) together. In the same year, Hornig became the editor-in-chief of "Pioniersmonatschau", a film magazine that had been set up in 1951 and that dealt with the life of members of the pioneer organization in short segments.

With "Tageskurs 1:4", a documentary film about the consequences of the currency exchange on October 13, 1957, Harry Hornig made his debut as a director in 1957. The film was followed by documentary films like "Energie" (1958) about the production of a heat generator in the Berzdorf power plant, "Alltag eines Poeten" (1961) about the locomotive driver and lyric poet Werner Barth, and "Auf der Strecke" (1963), the personal portrait of two railway men. In "Pankoff" ("Pankoff. An All-German Affair", 1965), Hornig exhibited West Germans and their understanding of the German Democratic Republic. In 1973, Hornig together with Joachim Hellwig, Uwe Belz, and Jürgen Böttcher presented "Wer die Erde liebt", the accompanying film to the 10th World Festival of Youth and Students in Berlin – the filmmakers were awarded with the GDR’s artistic prize for their film.

Hornig also produced documentary films for the GDR television. In his function as deputy head of the TV branch of DEFA-Studio für Kurzfilme, Hornig finished several films, including "Trautes Heim, Glück allein" (1963), a reportage that deals with the problems of the housing situation in the German Democratic Republic.

Overall, Harry Hornig's films cover two areas that diverge both in form and in content: On the one hand, he made sensitive portraits of worker personalities that closely approach its protagonists and rely alone on the power of observation without any ideological filter. On the other hand, Hornig also illustrated his belief in the Socialist nation in films with a clearly propagandistic impetus.

Besides his cinematic work, Harry Hornig was also involved in film politics. Between 1972 and 1988, he was a board member of the section "Dokumentarfilm und Fernsehpublizistik" of the association of GDR film and TV makers. He also served as the chairman of the board from 1979 to 1982. Furthermore, he taught documentary film directing at Hochschule für Film und Fernsehen. From 1983 on, he was the head of the school's department for film directing for three years. Later, he became the prorector for education, film and TV production. In addition, Hornig also taught at Munich's Hochschule für Fernsehen und Film, at Bochum's Ruhr-Universität, and at the adult education centre of his native city Gelsenkirchen.

From the early 1980s on, Harry Hornig more and more withdrew from filmmaking. Instead, he increasingly worked as a writer and dramaturg for director Róza Berger-Fiedler, in particular. Together, they finished "Liebster Dziodzio" (1981), among other films. In 1991, Hornig and Berger-Fiedler set up the Berlin-based production company BABEL Film und Video GmbH and worked as a writer, dramaturg, and consulting producer for the company.

Harry Hornig died December 24, 2022, age 92.