Hildegarde Haas was born in Frankfort, Germany on April 19, 1926.  Her parents moved to the U.S. in 1937. Her education included summer classes at the Colorado Springs Fine Art Center followed by two years at the University of Chicago. Receiving a scholarship to the Art Students League, she studied under Vaclav Vytlacil and Morris Kantor. She was completely self-taught as a printmaker and explored the woodcut medium with other students at the ASL and "learned as she went." Haas was a member of The Printmakers, an established group of New York graphic artists whose ranks included Ross Abrams, Seong Moy, William Rose, Peter Kahn, Ruben Reif, Jim Forsberg, Wolf Kahn, Dorothy Morton, and Aaron Kurzen.

Haas had a condition called "synesthesia" which allowed her to visualize music she heard and she would work while listening to music. Her woodcuts, which lean toward rhythmic and calligraphic abstraction, were included in the exhibition "Young American Printmakers" at the Museum of Modern Art, New York in 1953. She exhibited nationally at juried exhibitions and her work frequently drew comments by critics highlighting these shows. The physical demands of carving her own blocks and hand printing each impression were too great so after seven years she put down her knives and gouges and exchanged them for brushes.

After relocating to Northern California in 1951, Haas became affiliated with Bay Area art organizations, including the San Francisco and Oakland Art Associations and the Arts and Crafts Coop in Berkeley. Haas continued to exhibit in national and local painting and print exhibitions and she had solo exhibitions at the Dallas Museum of Fine Arts and the Kaiser Aluminum Corporation. Her work is represented in the permanent collections of Museum of Modern Art, Library of Congress, City of San Francisco, Seattle Museum of Fine Art, Dallas Museum of Fine Art, Worcester Art Museum and the Cleveland Art Museum.

Hildegarde Haas died in Berkeley, California on October 25, 2002.