Eco may refer to:
Arts and entertainment
- Eco (video game), a 1988 life simulation game
- Eco (2018 video game), a 2018 simulation game
- Emil Chronicle Online, a 2005 Japanese MMO computer game
- English Chamber Orchestra, based in London
- Eco, a character in the Dragonar Academy light novel series
- Eco, a fictional substance in the Jak and Daxter games
- Eco, a character on the children's show The Shak
Government and politics
- Economic Cooperation Organization, an international organization
- Environment and Conservation Organisations of Aotearoa New Zealand
- Environmental Commissioner of Ontario
- European Communications Office
Technology
- .eco, a top-level domain for the Internet
- ECO (software framework)
- Engineering change order
Other uses
- Eco (currency), a proposed currency
- ECO: A Covenant Order of Evangelical Presbyterians, a Christian denomination
- Ecology
- Edison Chouest Offshore, an American shipbuilder
- Encyclopaedia of Chess Openings
- Energy Company Obligation, a government scheme in Great Britain
- Environmental Children's Organization, a children's environment organization founded by Severn Suzuki in the 1990s
- Equity carve-out
- Esporte Clube Osasco, a Brazilian football club
- Eternally collapsing object
- Noticias ECO, a defunct television network
- Umberto Eco (1932–2016), Italian philosopher, semiotician, novelist