The Maryland Interscholastic Athletic Association (M.I.A.A.) is a boys' sports conference for private high schools generally located in the Baltimore metropolitan area but extending to various other regions, including the state's mostly rural Eastern Shore. The M.I.A.A. has 27 member schools and offers competition in 17 sports. In most sports, it offers multiple levels of competition, including Varsity, Junior Varsity, and Freshmen-Sophomore teams, and the conference is broken down by separate leagues in each. In addition, members are sorted in accordance to continual performance; categories include 'A', 'B', or 'C' Conferences. Teams of the Association (League) may move up or down according to their performance spanning over the course of a year or so to maintain the competition at appropriate levels. Such levels vary for each sport; a school with a "B-Conference" lacrosse team can have an "A-Conference" soccer team: it all depends on the athletic performance of that particular sport.

Seven members of the M.I.A.A. (along with non-MIAA member St. Maria Goretti) also form the Baltimore Catholic League in boys basketball. In addition, many of the same schools compete in the simultaneously organized, all-female "Interscholastic Athletic Association of Maryland" in various girls' sports, together with the all-female schools of the same region.

Formed in 1994, the M.I.A.A., was the successor organization for boys to the former Maryland Scholastic Association, formed in 1919, through the leadership of Dr. Phillip H. Edwards.

In 2010, MIAA commissioner Rick Diggs said that a proposed merger with the Washington Catholic Athletic Conference would not be merging for football.^[1]

• Official website