Haas can refer to:
- Haas School of Business (United States), a part of the University of California, Berkeley, named after Walter A. Haas, Jr.
- Haas Automation, a machine tool company
- Haas effect, a psychoacoustic effect, also known as the Precedence Effect or law of the first wave front, named for Helmut Haas
- Haas Pavilion (United States), home of the University of California at Berkeley's basketball teams, named after Walter A. Haas
- Newman/Haas Racing, an auto racing team in the Champ Car series co-owned by Paul Newman and Carl Haas
- A common misspelling of the Hass variety of avocado.
- the Seri name of the Honey Mesquite, Prosopis glandulosa
- Hardware as a Service
Haas as a surname can refer to:
- Arthur Erich Haas (1884–1941), Austrian physicist
- Bernt Haas (b. 1978), professional football (soccer) player
- Bill Haas
- Bob Haas (b. 19??), Chairman of Levi Strauss & Co.
- Carl Haas (b. 1930), American auto racing impresario
- Charles F. Haas
- Charles S. Haas
- Charlie Haas (b. 1972), American professional wrestler
- Christl Haas (1943–2001), Olympic skiing champion for Austria
- Hugo Haas (1901–1968), Czech film actor, director and writer
- Clark Haas
- Conrad Haas (1509–1576), Austrian military engineer
- Darius de Haas
- David Haas
- Dick Haas (DOB unknown), former president of Speedblock
- Dolly Haas (1910–1994), German-American actress
- Eddie Haas
- Eduard Haas (b. ????), Austrian inventor of PEZ candy in 1927
- Ernst Haas (1921–1986), Austrian photographer and photojournalist
- Ernst B. Haas, American political scientist
- Frank Joseph Haas, former Grand Master of the Grand Lodge of West Virginia
- Fred Haas (c. 1915–2004), American golfer
- Fritz Haas (1890–1968), Austrian architect
- Fritz Haas (1886–1969), German malacologist
- Geertruida de Haas-Lorentz
- Gene Haas
- Georg Haas (physician) (1886–1971), German medical doctor
- Georg Haas (zoologist) (1905–1981), Israeli herpetologist and paleontologist
- Hans Haas (1886–1935), German Protestant theologian
- Helmut Haas (b. ????), discoverer of the Haas effect
- Hugo Haas (1901–1968), Czech film actor and director
- Jacob de Haas
- Jason Haas (b. 1972), American Survey Legend
- Jay Haas
- Josef Haas
- Joseph Haas (1879–1960), German composer
- Karen L. Haas
- Karl Haas (1913–2005), American classical music radio show host
- Lukas Haas (b. 1976), American film actor
- Mario Haas
- Mary Haas (1910–1996), American linguist
- Mauritz de Haas
- Monique Haas (b.1909–1987), French pianist
- Moose Haas
- Mule Haas
- Nico de Haas
- Pavel Haas (1899–1944), Czech Jewish composer
- Richard Haas
- Robert Haas (clergyman), German Lutheran minister
- Robert Haas (musicologist)
- Russ Haas (b. 1974–2001), American professional wrestler
- Saskia Rao-de Haas
- Sidney V. Haas, M.D. (1870&ndash1964), American pediatrician and originator of the Specific Carbohydrate Diet
- Thomas J. Haas
- Tommy Haas (b. 1978), German tennis player
- Wander Johannes de Haas
- Walter A. Haas (1889–1979), former President and Chairman of Levi Strauss & Co.
- Walter A. Haas, Jr. (b. 19??), former president, CEO, and chairman of Levi Strauss & Co.
- Walter H. Haas, American amateur astronomer, founder of the Association of Lunar and Planetary Observers (ALPO)
- Waltraut Haas (born 1927), Austrian actress and singer
- Wolf Haas (born 1960), Austrian author
- Wolfgang Haas
See also