MIAA

MIAA may refer to:
 * Maine Intercollegiate Athletic Association, defunct athletic conference of schools in Maine
 * Manila International Airport Authority, transportation agency in the Philippines
 * Maryland Interscholastic Athletic Association, high school athletic conference for private schools in the Baltimore Metro area
 * Massachusetts Interscholastic Athletic Association, high school athletic association governing 33 varsity sports throughout Massachusetts
 * Michigan Intercollegiate Athletic Association, athletic conference of NCAA Division III schools in Michigan and Indiana
 * Mid-America Intercollegiate Athletics Association, athletic conference of NCAA Division II schools in Kansas, Missouri, Nebraska, and Oklahoma
 * TRNA dimethylallyltransferase, an enzyme