The Oakland Activities Association was first formed with schools from an amalgamation of different leagues. The G.O.A.L. (Greater Oakland Activities League), Metro Suburban Activities Association and the Southeastern Michigan Association (plus one independently associated school) were all merged in 1994 into the Oakland Activities Association, with the goal being to form a more geographically-centered league.
Charter members After its first year, the OAA experienced rapid growth, with
Pontiac Central from the Saginaw Valley Association and
Oak Park from the Suburban Athletic League joining in 1995, and
Auburn Hills Avondale,
Clawson,
Madsion Heights Lamphere, and
Madison Heights Madison all coming to the OAA in 1996 after the disbandment of the Macomb-Oakland Athletic Conference. The next major growth period did not occur until 2002, when
Farmington,
North Farmington, and
Farmington Hills Harrison from the
Western Lakes Activities Association as well as the newly built
Stoney Creek High School in Rochester Hills all joined the OAA. 2002 also marked a period of decline for the OAA, beginning with Brandon High leaving to join the
Flint Metro League, where it currently resides in. Two years after that, in 2004, Madison and Lamphere left to join the
Macomb Area Conference, while Clawson left to join the Metro Conference, and in 2008, Waterford Mott and Waterford Kettering left to join the
Kensington Lakes Activities Association. However, in 2010, the OAA gained a new member in
Oxford, who had come from the Flint Metro League. After that, the next school to leave the OAA for another conference did not come for another 11 years, when Hazel Park left to join the
Macomb Area Conference in 2019. However, the OAA has been beginning to fill these holes in their membership, extending an invitation to
Ferndale University in 2020, who had been co-oping with Ferndale for football for years, and extending another invitation to their first non-Oakland County school in
Harper Woods, who was previously an independent, in 2021. There have also been a significant number of closings and consolidations of various Oakland County schools in recent years, which has also not helped the OAA's membership. These aforementioned consolidations are
Dondero High School closing and merging with Kimball High School to create
Royal Oak High School in 2006,
Pontiac Central High School closing and merging with
Pontiac Northern High School to create
Pontiac High School in 2009, Lahser High School closing and merging with Andover High School to create
Bloomfield Hills High School in 2013,
Southfield-Lathrup High School closing and merging with Southfield High School to create
Southfield Senior High School for the Arts and Technology (commonly abbreviated to Southfield A&T) in 2016, and Harrison High School closing in 2019. In 2027/2028,
Northville High School and
Novi High School are set to join the OAA. ==Member schools==