The Reagan Era or Age of Reagan is a periodization of recent American history used by historians and political observers to emphasize that the conservative "Reagan Revolution" led by President Ronald Reagan in domestic and foreign policy had a lasting impact. It overlaps with what political scientists call the Sixth Party System. Definitions of the Reagan Era universally include the 1980s, while more extensive definitions may also include the late 1970s, the 1990s, the 2000s, the 2010s, and even the 2020s. In his 2008 book, The Age of Reagan: A History, 1974–2008, historian and journalist Sean Wilentz argues that Reagan dominated this stretch of American history in the same way that Franklin D. Roosevelt and his New Deal legacy dominated the four decades that preceded it.

Upon taking office, the Reagan administration implemented an economic policy based on the theory of supply-side economics. Taxes were reduced through the passage of the Economic Recovery Tax Act of 1981, while the administration also cut domestic spending and increased military spending. Increasing deficits motivated the passage of tax increases during the George H. W. Bush and Clinton administrations, but taxes were cut again with the passage of the Economic Growth and Tax Relief Reconciliation Act of 2001. During Clinton's presidency, Republicans won passage of the Personal Responsibility and Work Opportunity Act, a bill which placed several new limits on those receiving federal assistance.