A haystack is a stack of hay.
Haystack or Haystacks may also refer to:
People Haystak (born 1973), American rapper Haystacks Calhoun (William Calhoun; 1934–1989), American professional wrestler Giant Haystacks (Martin Ruane; 1946–1998), British professional wrestler
Places Australia Haystack, Queensland Haystack Island, an island in South Australia
Canada Haystack, Newfoundland and Labrador
United Kingdom Haystacks (Lake District), a mountain in England
United States Haystack, New Mexico, a census-designated place Haystack Observatory, a group of radio-telescope astronomical observatories in Massachusetts Haystack Rock, a formation just off the coast at Cannon Beach, Oregon Hayward, California, nicknamed Haystack The Haystacks, enigmatic sandstone mounds in Loyalsock Creek, Sullivan County, Pennsylvania
Science and technology Haystack (MIT project), a personal information management/semantic web research software project Haystack (software), a network traffic obfuscator and encryptor deepset Haystack, an open source Python framework for building LLM applications
Other Haystack (food), an American dish Haystacks: Autumn, a c. 1874 painting by Jean-François Millet Haystacks (Monet series), a series of Impressionist paintings by Claude Monet Haystack Prayer Meeting, which led to the development of American Protestant missions in the 19th century Mogote, a haystack-shaped, erosional, geomorphic structure
See also Haystack Mountain (disambiguation)