CLO
- Alberto Clò
- Alfonso Bonilla Aragón International Airport
- Campylobacter-like organism test
- Cee Lo
- Central Legal Office
- Chief Learning Officer
- Chief Legal Officer
- Chlorine monoxide
- Civic Light Opera (disambiguation)
- Clodovil Hernandes
- Clothing insulation
- Clover Stornetta Farms
- Collateralized loan obligation
- Color Light Output
- Congress of Labor Organizations
- Conselh de la Lenga Occitana
- Coolaroo railway station
- Cooperative Living Organization
- Cło, Świętokrzyskie Voivodeship
- Federation of Civil Service Organizations
- Hypochlorite