AEI may refer to: Adelaide Educational Institution of South Australia Aei Latin-script trigraph AEI Music Network Inc. (Audio Environments Incorporated), which created the "Foreground Music" industry in 1971 Albert Einstein Institute, the Max Planck Institute for Gravitational Physics, Germany Albert Einstein Institution, an organisation involved in non-violent methods of political resistance based in the US Alliance for European Integration, the ruling coalition in Moldova since the July 2009 election American Enterprise Institute, a conservative think tank Architectural Engineering Institute Archive of European Integration Associated Electrical Industries, large company in the UK (now defunct) Automatic Equipment Identification, as used by the railroad industry Average Earnings Index, British labour market measure Average Earnings Index (horse racing), American horse racing measure Atomic Energy Organization State Research Agency, a Spanish state agency responsible for the promotion of scientific and technical research