Klemens Brosch was born on 21 October 1894 in Linz. Already as a child he was drawn to the botanical, photographic, and graphic work of his father and his brother Franz. Brosch graduated from the Imperial Royal State Oberrealschule and after that he graduated from the Academy of Fine Arts in Vienna under Professor Ferdinand Schmutzer. Already during the school years at the Linz Realschule Brosch did thousands of sketches. With his brother Franz and others, he found the Linz artists' association Maerz in 1913.
Arnold Böcklin, Max Klinger, and Alfred Kubin mainly influence Brosch’s graphic works. His technical mastery was created by an intense study of nature. With binoculars strapped to his eyes he sat on the grass to convert the visible phenomena in fine linear, highly realistic drawings. Brosch’s body of drawings includes several thousands sheets. Much of it is located in the Upper Austrian museums:
Landesmuseum, Nordico Museum of the City of Linz, the Lentos Art Museum, as well as privately owned.
Klemens Brosch died on 17 December 1926 in Linz.