NCA
- Amino acid N-carboxyanhydride
- European Banking Supervision
- European Union competition law
- Lithium nickel cobalt aluminium oxides
- NC.A
- National Campaign for the Arts
- National Capital Authority
- National Character Area
- National Cheerleaders Association
- National Citizens Alliance
- National Climate Assessment
- National Coffee Association
- National College of Arts
- National Command Authority (Pakistan)
- National Command Authority (United States)
- National Communication Association
- National Computerization Agency
- National Conscription Agency
- National Conservation Area
- National Consumer Agency
- National Credentialing Agency for Laboratory Personnel
- National Cricket Academy
- National Crime Agency
- National Crime Authority
- National Cycling Association
- Nationwide Ceasefire Agreement
- Nature Conservation Act 1992
- Necessary Condition Analysis
- Neighbourhood components analysis
- Network Computing Architecture (disambiguation)
- Network of Concerned Anthropologists
- New Caledonia
- New Classical Adventure
- Nexus Computing Agent
- Ngorongoro Conservation Area
- Nicaragua
- Nigerian College of Accountancy
- Nippon Cargo Airlines
- Noise Control Act
- Non-compete agreement
- Nortel Certified Architect
- North Caicos Airport
- North Central Association of Colleges and Schools
- Norwegian Church Aid
- Norwegian Coastal Administration
- Nuclear Command Authority (India)
- Nuevo Central Argentino
- Urban community of Nice Côte d'Azur
- World Heritage Site