The American Enterprise Institute for Public Policy Research, known simply as the American Enterprise Institute (AEI), is a center-right think tank based in Washington, D.C., that researches government, politics, economics, and social welfare. AEI is an independent nonprofit organization supported primarily by contributions from foundations, corporations, and individuals.

A think tank, or policy institute, is a research institute that performs research and advocacy concerning topics such as social policy, political strategy, economics, military, technology, and culture. Most think tanks are non-governmental organizations, but some are semi-autonomous agencies within government, and some are associated with particular political parties, businesses or the military. Think tanks are often funded by individual donations, with many also accepting government grants.