- CER (Cherbourg - Maupertus Airport)
- CERA (Cambridge Energy Research Associates)
- CERCLA (U.S. Comprehensive Environmental Response, Compensation, and Liability Act (Superfund))
- CERCLIS (Comprehensive Environmental Response, Compensation, and Liability Information System (US))
- CERDEC (U.S. Communications-Electronics Research, Development and Engineering Center)
- CER-DIP (CERamic Dual In-line Package)
- CERE (cement remedial log)
- CERES (Coalition for Environmentally Responsible Economies)
- CERF (Central Emergency Revolving Fund)
- CERFP (CBRNE (Chemical, Biological, Radiological, Nuclear, and Explosive) Enhanced Response Force Package)
- CERG (Clean Energy Research Group)
- CERGA (Centre de recherches en géodynamique et astrométrie (French, "Astrometry and Geodynamics Research Centre"))
- CERI (Children's Emergency Relief International)
- CERL (Civil Engineering Research Laboratory)
- CERN (Centre européen pour la recherche nucléaire (French, "European Organization for Nuclear Research"))
- CERP (Commanders' Emergency Response Program)
- CERT (Computer Emergency Response Team)
- CERTI (Comprehensive Educational Restructuring And Technology Infusion)
- CERTS (Consortium for Electric Reliability Technology Solutions sposored by the United States Department of Energy and California Energy Commission (US))
- CERTSUB (CERTain SUBmarine)
- CES (Civil Engineering Squadron)