Cao
- Air China Cargo
- CA Oradea
- CA Osasuna
- Canadian Association of Optometrists
- Canadian Association of Orthodontists
- Cao (Chinese surname)
- Cao (Vietnamese surname)
- Cao (bull)
- Cao (footballer, born 1968)
- Cao (state)
- Cao Cao
- Cao County
- Cao Hamburger
- Cao Pi
- Cao Wei
- Cao Yu
- Cao Yupeng
- Carlos Alberto Caó
- Central Allocation Office
- Central Applications Office
- Centre for Adult Education
- Chief Administrative Officer of the United States House of Representatives
- Chief accounting officer
- Chief administrative officer
- Chief analytics officer
- Child Arrangement Order
- Chlorophyllide-a oxygenase
- Civil Aviation Office
- Cold air outbreak
- Commission on Audit
- Compliance Advisor/Ombudsman
- Cão!
- Diogo Cão
- Iran Civil Aviation Organization
- Joseph Cao
- Lady of Cao
- Longbing Cao
- Magdalena de Cao
- ORiN
- Provost (education)