AAB
AAB or Aab may refer to:

Organizations 

 Aalborg Boldspilklub, a sports club in Aalborg in Denmark
 AaB A/S, Aalborg Boldspilklub A/S, a Danish company and the professional part of Aalborg Boldspilklub
 ABN AMRO, the largest bank in the Netherlands
 Act Against Bullying, a UK charity
 Akita Asahi Broadcasting, a television station in Akita Prefecture, Japan
 Arubaanse Atletiek Bond, the governing body for the sport of athletics in Aruba
 Athletics Association of Barbados, the governing body for the sport of athletics in Barbados
 Association of Applied Biologists, a UK-based learned society promoting applied biology

Aviation and military 

 Air Assault Badge, a United States Army military badge
 Arrabury Airport in Queensland, Australia
 Abelag Aviation in Belgium
 Anti-aircraft battery, a weapons system component for anti-aircraft warfare

Other uses 
 Aab (surname)
 Alice Bailey, new age writer often referred to by her initials as AAB
 Acetic acid bacteria, classified under alphaproteobacteria which are used in making vinegar
 Akbar Al Baker, Qatar Airways CEO often referred to by his initials as AAB
 Alumu language, a Niger–Congo language of Nigeria
 Aniline Yellow or aminoazobenzene
 Antigua and Barbuda
 Atlas of Australian Birds, two books and a database of the Royal Australasian Ornithologists Union
 Auto-aggressive behaviour, aka self-harm
 AAB is also used to characterize the structure of verses in blues music, known as call and response