The Reagan era or the 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, and even the 2000s. 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.

Conservatism in the United States is based on a belief in limited government, individualism, traditionalism, republicanism, and limited federal governmental power in relation to U.S. states. It is one of two major political ideologies of the United States. Conservative and Christian media organizations and American conservative figures are influential, and American conservatism is a large and mainstream ideology in the Republican Party and nation. As of 2021, 36 percent of Americans consider themselves conservative, according to polling by Gallup, Inc.