Eureka often refers to:

• Eureka (word), a famous exclamation attributed to Archimedes
• Eureka effect, the sudden, unexpected realization of the solution to a problem

Eureka or Ureka may also refer to:

• Eureka Rebellion, an 1854 goldminers' rebellion in Ballarat, Victoria, Australia
  • Eureka Flag, the battle flag of the Eureka Rebellion
• Tehran Conference, codenamed Eureka, an Allied meeting during World War II

• Eureka (company), a manufacturer of vacuum cleaners
• Eureka! Restaurant Group, California-based hamburger restaurant chain
• Eureka! Tent Company, an American company
• Kværner Eureka, a Norwegian engineering and construction services company

• Eureka O'Hara, an American drag queen, popularized on Rupaul's Drag Race
• Eureka (Oz), Dorothy Gale's cat in The Wizard of Oz, so named because Uncle Henry found her
• Eureka (Eureka Seven), a main character in Eureka Seven

• Eureka (1983 film), a British-American drama directed by Nicolas Roeg
• Eureka (2000 film), a Japanese drama directed by Shinji Aoyama
• Eureka (2020 film), an Indian Telugu-language thriller film by Karteek Anand
• Eureka (2023 film), an Argentine drama directed by Lisandro Alonso
• Eureka! (Canadian TV series), a 1980s Canadian educational series
• Eureka! (2022 TV series), a 2020s American educational series
• Eureka (British TV series), a 1980s British educational series
• Eureka (2006 TV series), an American science fiction series aired 2006–2012
  • Eureka (soundtrack), a 2008 soundtrack album
• Eureka TV, a British children's science show aired 2001–2005
• Eureka Learning Channel, a defunct Singaporean educational television channel

• Eureka (Jim O'Rourke album), whose title track was featured in the 2000 film
• Eureka (Mother Mother album)
• Eureka (Rooney album), 2010
• Eureka (Leslie Clio album)
• "Eureka" (Sakanaction song), 2014 song by Sakanaction
• "Eureka" (Gen Hoshino song), 2025 song by Gen Hoshino

• Eureka (University of Cambridge magazine), published by the Cambridge University Mathematical Society
• Eureka (Italian magazine), a monthly comic magazine published between 1967 and 1989
• Eureka (Japanese magazine) [jp], a monthly general art magazine with a focus on poetry and criticism
• Eureka: A Prose Poem, a 1848 essay by Edgar Allan Poe
• Eureka, a monthly science magazine for primary school students in Malayalam language published by Kerala Sasthra Sahithya Parishad, Kerala, India
• Eureka (journal), the original name of the Canadian mathematical problem-solving journal Crux Mathematicorum

• Eureka (musical), a 2004 Australian musical
• Eureka! (video game), a 1984 text adventure

• Eureka, New South Wales, a suburb in Byron Shire
• Eureka, Queensland, a locality in the Bundaberg Region
• Eureka, Victoria, a small eastern suburb of Ballarat

• Eureka, Nova Scotia
• Eureka, Nunavut
• Eureka Pass, Axel Heiberg Island, Nunavut
• Eureka Sound, Nunavut

• San Antonio de Ureca, also called Ureka, on Bioko Island and known as one of the wettest places on Earth

• Eureka, New Zealand, rural settlement in the Waikato District

• Eureka, California, the largest US city named Eureka
• Eureka, Colorado
• Eureka, Marion County, Florida
• Eureka, Miami-Dade County, Florida, part of Richmond West, Florida
• Eureka, Illinois
  • Eureka College
• Eureka, Lawrence County, Indiana, an unincorporated community
• Eureka, Spencer County, Indiana, an unincorporated community
• Eureka, Kansas
• Eureka, Michigan, an unincorporated community
• Eureka, Missouri
• Eureka, Perry County, Missouri
• Eureka, Montana
• Eureka, Nevada
• Eureka, North Carolina
• Eureka, Oregon, an unincorporated community and ghost town
• Eureka, Pennsylvania
• Eureka, South Carolina, an unincorporated community in Aiken County, South Carolina
• Eureka, South Dakota
• Eureka, Texas (disambiguation)
• Eureka, Utah
• Eureka (Baskerville, Virginia), a historic home near Baskerville, Mecklenburg County, Virginia
• Eureka, Washington
• Eureka, West Virginia
• Eureka, Polk County, Wisconsin, a town
• Eureka, Winnebago County, Wisconsin, an unincorporated community
• Eureka Center, Minnesota
• Eureka Center, Wisconsin
• Eureka County, Nevada
• Eureka Springs, Arkansas
• Eureka Township, Adair County, Iowa
• Eureka Township, Michigan
• Eureka Township, Dakota County, Minnesota
• Eureka Township, Valley County, Nebraska
• Eureka Valley (Inyo County), California
• Eureka Valley, San Francisco, California

• Eureka (organisation), an international research and development funding and coordination network
• Eureka (OPAC), a library search engine developed by RLG
• Eureka! (museum), a museum in Halifax, West Yorkshire, United Kingdom
• The Eureka, a machine for generating Latin verses
• Eureka-147, a system for digital audio broadcast
• Eureka Streams, an open source software project
• Eureka theorem, a result of Gauss that every natural number is the sum of three triangular numbers
• 5261 Eureka, an asteroid co-orbital with Mars
• Constantan, also known as Eureka, a metal alloy
• Heureka, a science centre in Vantaa, Finland
• Eureka, the transponder component of the World War II Rebecca/Eureka transponding radar
• Eureka: The Solver, numerical solver for mathematical systems of equations, released by Borland, 1987

• Eureka (1900 automobile), an American automobile
• Eureka (1907 automobile), an American automobile
• Eureka (airship), a Zeppelin NT owned by Airship Ventures
• Eureka (French automobile), a French automobile
• Eureka (ferryboat), an 1890-built steam ferryboat now preserved in San Francisco
• Ameri-Cana Eureka, a Canadian ultralight aircraft

• Eureka Diamond, the first diamond found in South Africa
• Eureka Mountain (Colorado), a summit in the Sangre de Cristo Range
• Eureka Poker Tour, poker tour in the central and eastern Europe
• Eureka Prizes, annual Australian science prizes presented by the Australian Museum, Sydney, Australia
• Eureka Shipyard, a shipyard of the early 20th century in New York State
• Eureka Tower, a 2006 91-storey residential building in Melbourne, Australia
• Disney's Eureka! A California Parade, a former parade in Disney's California Adventure Park
• Eureka! Program, a teen girls' achievement program run by Girls, Inc.
• Asociación Atlética Eureka, known as Eureka, a former football team in Argentina
• Eureka O'Hara, American drag queen

• EURECA (disambiguation)
• Eurekha, 1999 biography of Indian actress Rekha by Mohan Deep