CSO may refer to:
- Any of a number of government statistics organizations:
- Central Statistical Office (disambiguation)
- Czech Statistical Office (Český statistický úřad, ČSÚ, sometimes also abbreviated CZSO)
- Central Statistical Organisation, India
- other offices:
- Chief Scientist Office of the Scottish government
- Officers:
- Chief Science Officer
- Chief security officer
- Chief strategy officer
- Chief sustainability officer
- Combat Systems Officer (U.S. Air Force)
- Police Community Support Officer (UK)
- Community Service Officer (US)
- Consumer Safety Officer, a position title used by the Food and Drug Administration
- Court security officer (disambiguation)
- Symphony orchestras:
- Canberra Symphony Orchestra
- Chicago Symphony Orchestra
- Christchurch Symphony Orchestra
- Cincinnati Symphony Orchestra
- Columbus Symphony Orchestra
- Organizations:
- Coastal States Organization
- Contract sales organization
- Civil Society Organization
- Other:
- colour-separation overlay (chroma key)
- Combined sewer overflow
- Compulsory Stock Obligation
- .CSO, compressed file format for ISO disc images
- Counter-Strike Online, 2008 video game
- Credit Spread Options
- Caltech Submillimeter Observatory, Mauna Kea, Hawaii
- CSO, the IATA airport code for Magdeburg-Cochstedt Airport, Germany