The American Institute of Architects (AIA) St. Louis is the local chapter of The American Institute of Architects, headquartered in Washington, DC. The AIA represents over 94,000 architects in the United States.

AIA St. Louis provides professional growth and development opportunities for more than 880 architects and architectural interns members in the Eastern half of Missouri. It is the organized voice of the architect in St. Louis that provides support to members, advocates on issue affecting the profession and public safety and comments on policy regarding the built environment.