See also: Appendix:Variations of "asa"
- (sports) Abbreviation of American Samoa.
- Initialism of Acoustical Society of America.
- Initialism of American Standards Association, which has changed its name to American National Standards Institute (ANSI).
- Initialism of American Society of Anesthesiologists.
- Initialism of Amateur Swimming Association.
- (Britain) Initialism of Advertising Standards Authority.
- (military) Initialism of air sovereignty alert: refers to fighter jet units that provide aerial defense of the nation via high-readiness aircraft.
- (pharmacology, uncountable) Initialism of acetylsalicylic acid. (aspirin)
- (aspirin): APAP (tylenol)