- Amateur Athletic Association of America
- American Association for the Advancement of Agnosticism
- American Association for the Advancement of Atheism
- American Association for Affirmative Action
- American Association of Advertising Agencies
- Antique Aeroplane Association of Australia
- Antique Appraisal Association of America
- Army Aviation Association of America
- Associated Actors and Artists of America
- (Singapore) Association of Accredited Advertising Agencies
- Australian Advertising Advisory Authority
- Australian Association of Advertising Agencies
- Australian Automotive Aftermarket Association
- "Authentication, Authorization, Accounting, and Auditing", the four main services provided by an Internet Authentication Service.
AAAA (plural AAAAs)
- A specific size and configuration of electric battery.
- (slang) A baseball player who is too good for Minor League Baseball, but not good enough for Major League Baseball.
- Aa type of DNS record used to indicate the IPv6 internet address of a DNS name.