1aa

1AA is an alphanumeric designation used in different contexts. The most widely cited usage is as a shorthand for the NCAA Division I Football Championship Subdivision designation I-AA, the second tier of Division I college football. Beginning in 1978, NCAA Division I was subdivided into I-A and I-AA; I-AA teams competed in a playoff system to determine the national champion. In 2006 the subdivision was renamed the Football Championship Subdivision (FCS). In contemporary writing the official term is FCS, but the forms "I-AA" and occasionally "1AA" appear in historical accounts and some media references.

Outside of college football, "1AA" can function as a generic catalog or item code in various contexts. It does not correspond to a single universal standard; its meaning depends on the issuing organization and is not widely standardized.

Notable universities that competed in I-AA include Appalachian State, Montana, and Delaware, among others; these programs later moved to the FBS or continued in the FCS lineage as the NCAA reorganized its subdivisions. See also I-AA, FCS, NCAA Division I football.