It can stand for Aisa Joy, Adam Jonathan, Abby Jeffrey, or Al Jacobsin.
A. J. Foyt's family name is Foyt.
Andrew John
AJ stands for Andrea Joy. AJ is affectionately known as Dre by close family and friends.
When AJ is used in reference to the US Supreme Court, it means "Associate Justice," the formal title of the eight justices who serve under the Chief Justice.