NECA or Neca may refer to:
National Entertainment Collectibles Association, an American merchandise licensee of film and television for the enthusiast market National Electrical Contractors Association, an American trade association NECA Show, electrical construction industry's trade show since 1901 National Exchange Carrier Association, an American association of telephone common carriers Neca (footballer) (born 1979), real name João Alexandre Duarte Ferreira Fernandes, Portuguese footballer NECA Project, Net Environment for Embodied Emotional Conversational Agents Nitrous Oxide Emission Control Area, sea areas with regulated nitrous oxides emission caps North East Combined Authority (2014–2024), a former local government body in North East England North East Combined Authority, a local government body in North East England 5′-(N-Ethylcarboxamido)adenosine (NECA), a reference agonist for adenosine G protein-coupled receptors; see Adenosine A2A receptor