| CI | Chemical Ionization | - | Computer Acronyms(common) |
| CI | Compression-ignition (engine) | - | Computer Acronyms(common) |
| CI | Configuration Interaction | - | Computer Acronyms(common) |
| CI | ContraIndications | - | Medical(slang) |
| CI | Certification Inspection | - | Organizations |
| CI | Color Interior Film | - | Organizations |
| CI | Configuration Inspection | - | Organizations |
| CI | Configuration Item | - | Organizations |
| CI | Continuous Interlock | - | Organizations |
| CI | Course (deviation Display) Invalid | - | Organizations |
| CI | Crew Interface | - | Organizations |
| CI | Chile (FIPS 10-4 Country Code) - C?te D'Ivoire (ISO 3166 Digram) -Counter-Intelligence | - | Astronomy |
| CI | Curie | - | Astronomy |
