Ronald Reagan (6 February 1911 – 5 June 2004) was the 40th President of the United States, serving two terms from 1981 to 1989. Before entering politics, he worked as a radio broadcaster, film and television actor, and served as president of the Screen Actors Guild. He was governor of California from 1967 to 1975 before winning the Republican presidential nomination in 1980 and defeating incumbent president Jimmy Carter in a landslide. Reagan's presidency coincided with a significant rightward shift in American politics, the final decade of the Cold War, and a period of major economic policy change. He remains one of the most consequential and debated American presidents of the twentieth century.

Reagan was born in Tampico, Illinois, to a working-class family. He attended Eureka College and built a career in entertainment before his political views shifted from New Deal liberalism toward anti-communist conservatism in the late 1940s and 1950s, partly through his work combating alleged Communist influence in Hollywood. He gained national political visibility through a 1964 televised speech supporting Barry Goldwater's presidential campaign, known as “A Time for Choosing.” His two terms as California governor established him as a leading figure of the modern conservative movement. See Reagan – History for a full account.

Reagan entered office during a period of high inflation, elevated unemployment, and low public confidence following the Iranian hostage crisis. His domestic program, labeled “Reaganomics” by supporters and critics alike, centered on significant cuts to marginal income tax rates, reductions in domestic spending, deregulation, and tight monetary policy to combat inflation. The Federal Reserve's contractionary policy contributed to a severe recession in 1981–82, followed by sustained economic growth for most of the remainder of his presidency. The national debt roughly tripled during his two terms. See Reagan Economic Policy – Debate.

In foreign policy, Reagan pursued an assertive anti-Soviet posture, significantly increasing defense spending, supporting anti-communist insurgencies under the Reagan Doctrine, and engaging in arms negotiations with Soviet General Secretary Mikhail Gorbachev. The Intermediate-Range Nuclear Forces (INF) Treaty was signed in 1987. The extent to which Reagan's policies contributed to the dissolution of the Soviet Union is a matter of significant historical debate; see Reagan and the Cold War – Debate.

The Iran-Contra affair (1986) involved covert arms sales to Iran and diversion of proceeds to Nicaraguan Contra rebels, later found illegal by Congressional investigators; Reagan's personal knowledge of the diversion remains disputed. See Iran-Contra – Debate.

Reagan's social policy agenda included opposition to abortion and support for school prayer, though few major social policy changes were enacted during his terms. His administration's response to the AIDS epidemic — including the timeline of federal action and Reagan's public statements — is a subject of significant debate. See Reagan and the AIDS Epidemic – Debate.

Reagan left office with high approval ratings and is consistently ranked by presidential historians among the upper tier of American presidents, though rankings vary considerably depending on the evaluative criteria and ideological commitments of the ranker. He is regarded by many conservatives as the defining figure of late-twentieth-century American conservatism. His critics argue that his policies deepened economic inequality, damaged the social safety net, fueled deficit spending, and set harmful precedents in foreign policy. The meaning and durability of his legacy remain actively contested across economics, foreign policy, and social history.

Broad expert consensus exists on several matters of historical fact regarding Reagan's presidency — the trajectory of macroeconomic indicators, the sequence of Cold War events, and the legal findings of the Iran-Contra investigations. Interpretive questions — including the causes of the 1980s economic expansion, Reagan's personal role in ending the Cold War, and the long-term effects of his tax and regulatory policies — remain the subject of genuine scholarly and public debate. See Reagan Economic Policy – Consensus and Reagan and the Cold War – Consensus.

The Conservative Icon Viewpoint holds that Reagan's presidency successfully restored American economic dynamism, rebuilt military strength after a period of decline, and played a decisive role in winning the Cold War, validating supply-side economic theory and assertive anti-communist foreign policy.

The Neoconservative Viewpoint assesses Reagan's defense buildup, the Reagan Doctrine, and his confrontational posture toward the Soviet Union as a vindication of peace-through-strength principles, and treats the Cold War endgame as a model for assertive democratic foreign policy.

The Pragmatic Centrist Viewpoint regards Reagan as a skilled political communicator who achieved some genuine policy successes — particularly on inflation and Cold War diplomacy — while falling short of his ideological goals and making significant pragmatic compromises, including tax increases and arms negotiations.

The Left-Critical Viewpoint argues that Reagan's policies increased economic inequality, weakened labor and regulatory institutions, expanded executive power in harmful ways, and that his legacy has been significantly inflated by admiring conservative accounts.

The Libertarian Viewpoint assesses Reagan as a president whose rhetoric of limited government was not matched by his record, noting that federal spending, deficits, and the regulatory state grew during his tenure, and criticizing his foreign interventionism and drug war policies.

The Historical Revisionist Viewpoint encompasses scholarly work that challenges both celebratory and harshly critical narratives, emphasizing contingency, the role of other actors (including Gorbachev), and reassessments of the empirical record on economics and foreign policy.

• Ronald Reagan – History
• Reagan and the Cold War – Debate
• Iran-Contra Affair – Debate
• Reagan and the AIDS Epidemic – Debate
• Reagan Economic Policy – Debate
• Reagan Economic Policy – Consensus
• Reagan and the Cold War – Consensus
• American Conservatism
• Cold War
• Supply-Side Economics
• Iran-Contra Affair

1. Lou Cannon, President Reagan: The Role of a Lifetime (PublicAffairs, 2000). Standard biographical and political account by a journalist who covered Reagan across his career.
2. H.W. Brands, Reagan: The Life (Doubleday, 2015). Comprehensive single-volume biography.
3. Sean Wilentz, The Age of Reagan: A History, 1974–2008 (Harper, 2008). Narrative history placing Reagan within a broader political era.
4. Robert M. Collins, Transforming America: Politics and Culture During the Reagan Years (Columbia University Press, 2007). Scholarly assessment of domestic policy and cultural change.
5. James Mann, The Rebellion of Ronald Reagan: A History of the End of the Cold War (Viking, 2009). Examines Reagan's role in Cold War diplomacy, particularly the Gorbachev relationship.
6. Frances FitzGerald, Way Out There in the Blue: Reagan, Star Wars and the End of the Cold War (Simon & Schuster, 2000). Focuses on SDI and its role in Cold War strategy and negotiations.
7. Norman Podhoretz, World War IV: The Long Struggle Against Islamofascism (Doubleday, 2007); and Irving Kristol, Neoconservatism: The Autobiography of an Idea (Free Press, 1995). Representative neoconservative assessments of Reagan-era foreign policy doctrine.
8. Report of the Congressional Committees Investigating the Iran-Contra Affair, S. Rep. No. 100-216, H. Rep. No. 100-433 (1987). Primary source for the Iran-Contra findings.
9. Economic Report of the President (various years, 1981–1989). Primary source for macroeconomic data during the Reagan administration.