Michael Medved was born into a Jewish family in Philadelphia, Pennsylvania, and was raised in San Diego, California, where his scientist father David Medved worked for the defense contractor Convair and later for NASA. Medved attended Palisades High School when the family moved to Los Angeles. He entered Yale University as a sixteen-year-old undergraduate, and graduated with honors in 1969, and then entered Yale Law School.

After his first year of law school, he left to work as a head speech writer for Democratic U.S. Senate candidate Joe Duffey, and then for four years as a speech writer and political consultant. After political campaign work, including a position as an aide to Congressman Ron Dellums, Medved worked in advertising, and coordinated a campaign to recruit more African Americans and Hispanics to the police departments of the California cities of San Francisco, Oakland and Berkeley.

After writing more than forty articles for the book The People's Almanac, Medved wrote What Really Happened to the Class of '65?, with David Wallechinsky. Focusing on the post-graduation lives of thirty of Medved's Palisades High School classmates who were featured in a 1965 cover story in Time, the book became a bestseller in 1976. The book also became the basis for a weekly TV series on NBC that ran for 13 weeks in 1978.

Medved then wrote The Shadow Presidents: The Secret History of the Chief Executives and Their Top Aides (1979), a study of the leading White House assistants since the establishment of the presidential staff in 1857. The book included interviews with the chiefs of staff of presidents Truman, Eisenhower, Kennedy, Johnson, Nixon, and Ford. After the interviews, Medved continued his involvement in politics, becoming a friend of Ford's chief of staff, Dick Cheney, affiliating himself with the Republican Party, and campaigning for Ronald Reagan in 1980.

In 1984, Medved wrote Hospital: The Hidden Lives of a Medical Center Staff, which was discussed in Time Magazine, on ABC's Nightline, and Good Morning America. The book focused on thirty staff people who worked together in a California teaching hospital.

Medved continued his screenwriting work, writing for feature film projects and TV miniseries, and he joined the Writers Guild of America. He also collaborated with his brother, Harry Medved, on four satirical books about movies: The Fifty Worst Films of All Time (1979), The Golden Turkey Awards (1980), The Hollywood Hall of Shame (1984) and Son of Golden Turkey Awards (1986).

Medved continued to review movies, through a weekly review on CNN (1980—1983) and a show he hosted on British network Channel 4 called The Worst of Hollywood. His commentary centered on what he considered to be bad movies, particularly in "The Golden Turkey Awards". The film selected by the Medved Brothers as The Worst Film of All Time, Plan 9 from Outer Space, has since become a cult classic.

In 1984, Medved joined Sneak Previews, the weekly movie review show originated by Gene Siskel and Roger Ebert, co-hosting the program for twelve years with Jeffrey Lyons.

In 1993, Medved became chief film critic for the New York Post, a position he held for five years, during which he reviewed more than 700 movies for the newspaper.

More recently, Medved has played a prominent role in some movie-related controversies. Medved became an outspoken defender of Mel Gibson's movie, The Passion of the Christ (2004), which had been criticized as antisemitic by many prominent Jewish groups. After Mel Gibson's DUI arrest in July 2006, Medved wrote that he felt "betrayed" by Gibson's antisemitic outburst and urged Gibson to seek "reconciliation" with the Jewish community.

Some film critics, including Roger Ebert and Jim Emerson, criticized Medved for mentioning the "right to die/assisted suicide" theme in Clint Eastwood's Oscar-winning Million Dollar Baby and these critics viewed Medved's statements as a plot spoiler. Medved stated that the inclusion of this theme in the film was "deeply misleading" because it was marketed as a Rocky-esque tale of a plucky female underdog in the boxing arena. Medved said that he carefully avoided revealing the final turn in the plot, but felt honor bound to inform his listeners and readers about the movie's content and provocative point of view. Roger Ebert criticized Medved, saying he "has for a long time been a political commentator, not a movie critic."

While focusing on the theme of Hollywood vs. America, radio talk show host Rush Limbaugh interviewed Medved and then asked Medved to guest-host his talk show. Medved went on to serve as a regular guest-host for Limbaugh on close to 30 occasions. In 1996, Medved was offered his own local show on a major Seattle radio station. In his 2005 autobiographical book Right Turns: From Liberal Activist to Conservative Champion in 35 Unconventional Lessons, Medved says he welcomed the chance to escape "the movie ghetto" and to speak to a wider audience about politics and morality, which were a focus of his written commentary and books. Medved's show was broadcast from Seattle and syndicated through Salem Radio Network.

His three hour daily show is now broadcast on 200 stations coast to coast and reaches more than 4.75 million listeners weekly.For ten consecutive years, Medved has been listed by Talkers magazine as one of its "Heavy Hundred" most important American talk show hosts, and recently tied for eighth place in its ranking of talk hosts by audience size.

Medved describes the show as "Your Daily Dose of Debate," often focused on listeners who call in to debate issues with the host. Guests have included those who are generally considered left-of-center, including Noam Chomsky, Michael Moore, John Shelby Spong, Oliver Stone, Warren Beatty, Ralph Nader, Barbara Boxer, Al Gore, Madeleine Albright, Ben Cohen, George Galloway, Thom Hartmann, Naomi Wolf, and Al Franken. Guests who are generally considered right-of-center include Robert Spencer, Condoleezza Rice, Dinesh D'Souza, and Jon Voight. Political independents who've appeared on the show include Christopher Hitchens.

Medved describes himself as "your cultural crusader on politics and pop culture" and common themes on his show include current events, politics, American history and the entertainment industry. He reviews four or more new movies or DVD releases per week. The program also includes a monthly "Conspiracy Day," which usually occurs within a few days of the full moon due to the superstitions surrounding that event, where callers from across the country expose what they consider the "hidden forces" behind "perplexing and painful present events."

Medved writes a regular column for USA Today and is a member of the Board of Contributors for USA TODAY's Forum Page, part of the newspaper’s Opinion section. He writes occasional op-ed pieces for The Wall Street Journal and blogs daily at Townhall.com. He also wrote the 1992 book Popular Culture and the War on Traditional Values, a condemnation of violence in cinema, which film critic David Denby in The New Republic called "the stupidest book about popular culture that I have read to the end."

In October 2007, Medved drew critics' fire after publishing a controversial column regarding the history of Slavery in the United States, in which he wrote, in part, "No, it’s not true that . . . America displayed unparalleled barbarity or enjoyed disproportionate benefit from kidnapping and exploiting innocent Africans" which led to his being featured as Keith Olbermann's "Worst Person In The World".

In November 2007, Medved became a senior fellow at the Discovery Institute, hub of the intelligent design movement.

In November 2008, Medved released his 11th nonfiction book The 10 Big Lies About America: Combating Destructive Distortions About Our Nation as a rebuttal to the historical fallacies he feels most Americans believe about their country. The follow up volume The 5 Big Lies About American Business: Combating Smears Against the Free-Market Economy was released in December of 2009.

He has argued that voters in the American Jewish community don’t necessarily embrace candidates based on their support for the state of Israel as much as they passionately oppose candidates based on their identification with Christianity, especially the fervent evangelicalism of the dreaded Christian Right. Medved also notes that the Orthodox community, which he states as less than 10% of the American Jewish population, "gives nearly as disproportionate support to Republicans as their Reform, Conservative, and secular Jewish neighbors give to Democrats," and argues that the main reason for this different response is that "[t]he Orthodox feel no instinctive horror at political alliances with others who make faith the center of their lives."

Medved co-founded Pacific Jewish Center, a synagogue in Venice, California, with his friend and teacher, Rabbi Daniel Lapin. For fifteen years, Medved served as president of PJC, which states that its mission is outreach to unaffiliated and disconnected Jews. In his book Right Turns: Unconventional Lessons from a Controversial Life, he states that his commitment to religion led to his conservative political outlook. He is a baal teshuva (returnee to traditional Judaism). Return of the Natives: OU Highlights Home Grown Talent at LATorah Convention, Dec 20-25 He is also known to be a vegetarian. Famous Vegetarians and Famous Vegans