He attended the Innsbruck School of Applied Arts and first came into contact with cinema in 1931.

He worked alongside Luis Trenker as an extra and assistant camera in the film "The Rebel" and at the same time he devoted himself to the profession of ski instructor and mountain guide.
In his spare time he produced his first films. These were films about youth culture and his beloved homeland such as "Schemenlaufen" or "Sommerlager".

When World War II broke out, Hörmann was drafted. After the deployments in Poland, he was forced to set up the photographic position at the Heeresgebirgsschule in Fulpmes. A series of documentary films date back to this period showing the training of soldiers in the mountains and during winter operations.

Later he was sent as a war correspondent with the "Schlebrügge" ski battalion. Field Marshal Bock commissioned Hörmann to make a "Film the war as it is", a documentary on the deployment of soldiers on the Eastern front. With the film material he collected, he produced a six-hour report on the madness of war. After being presented to Berlin executives, the film was confiscated and disappeared.

Returning from captivity in 1945, Hörmann mainly made non-fiction, educational and cultural films.

In the mid-1950s he founded his own production studio in Innsbruck.

Hörmann accompanied an Italian expedition to K2 with his camera. The result was "Kurs zum Dach der Welt" (Route on the roof of the world) and "Lied aus Lahore" (Song from Lahore).

Hörmann shot the official Olympic film "In the mountains of Tyrol", his only full production, for the 1964 Winter Olympics in Innsbruck. The film was dubbed in 12 languages, screened in 36 countries and won awards in Rome, Cortina and the Berlinale.

Hörmann's films have been distributed around the world and many have received coveted awards or the title of "precious".

Theodor "Theo" von Hörmann died in 1994 in Innsbruck.