Mark Reed Levin (born September 21, 1957, in Philadelphia, Pennsylvania) is a prominent American conservative radio host, author, lawyer, and political commentator. He grew up in Philadelphia, excelling academically and earning a B.A. in Political Science magna cum laude from Temple University Ambler at age 19. Levin began his career in public service during the Reagan administration, serving as chief of staff to Attorney General Edwin Meese III from 1986 to 1989, and holding positions at the U.S. Department of Justice, the Environmental Protection Agency, ACTION, and the U.S. Department of Education. After law school, he transitioned to private practice and began appearing as a guest on conservative talk radio shows, regularly contributing legal opinions to The Rush Limbaugh Show during the late 1990s Monica Lewinsky scandal, which caught the attention of Sean Hannity. In 2002, Levin launched his own nationally syndicated radio program, The Mark Levin Show, which became one of the top-rated talk programs, airing on over 400 stations and reaching millions of listeners. He expanded into television with the Fox News show Life, Liberty & Levin in 2018. Levin has authored several New York Times bestsellers, including Liberty and Tyranny (2009), Ameritopia (2012), The Liberty Amendments (2013), and Unfreedom of the Press (2019), which outline his constitutional conservative philosophy, promote originalism, critique liberalism, and defend constitutionalism. He served as president of the Landmark Legal Foundation, a conservative public interest law firm, from 1997 to 2018, and has been editor-in-chief of Conservative Review since 2015. He was a professional partner in the formation of Blaze Media through the merger of TheBlaze and CRTV. Levin was appointed to the Homeland Security Advisory Council by President Donald Trump in 2017 and maintains an active presence on social media and through LevinTV.

Levin's commentary is characterized by a staunch defense of American conservatism, originalism in constitutional interpretation, criticism of progressivism and government overreach, and focus on constitutional issues and national security, often delivered in a passionate, polemical style. He has been a frequent contributor to outlets like National Review and has appeared on programs hosted by Sean Hannity. Politically, Levin endorsed Ted Cruz in the 2016 Republican primaries before supporting Donald Trump, and he has been vocal in his opposition to what he terms the 'radical left' and 'deep state.' His Orthodox Jewish faith and Ashkenazi heritage inform aspects of his worldview, particularly on issues like Israel and religious liberty. He is recognized for his strong pro-Israel advocacy, criticism of U.S. foreign policy in the Middle East, and serving as a national spokesman for Move America Forward, a veterans' support organization. His work extends to education and media training through affiliations with the National Journalism Center. He collaborates on Conservative Review/Blaze projects, and commentator David Horowitz frequently guest hosts for him.

Levin resides primarily in the Washington, D.C. area with his second wife, Kendall Levin, whom he married after divorcing his first wife, Julie Strauss Levin; they have three children together from his first marriage. Throughout his career, Levin has faced criticism for inflammatory rhetoric, including accusations of promoting conspiracy theories about election fraud in 2020 and climate change denialism, drawing condemnation from media watchdogs, Democrats, and regulatory complaints. He has been involved in legal advocacy through Landmark Legal Foundation, filing lawsuits against government overreach, such as challenges to Affordable Care Act provisions, though his foundation has been scrutinized for its partisan activities. Levin has also faced bans on platforms like YouTube in 2021 for COVID-19 misinformation. No major personal legal troubles are documented. He remains an influential figure in conservative media, with a reported net worth exceeding $50 million derived from media, books, and legal work, shaping discourse on talk radio and television, and has been inducted into considerations for radio accolades.