Malkin, a Roman Catholic, attended Holy Spirit High School, where she edited the school newspaper and aspired to become a concert pianist. Following her graduation in 1988, she enrolled at Oberlin College. Malkin had planned to pursue a bachelor’s degree in music, but changed her major to English. During her college years, she worked as a press inserter, tax preparation aide, and network news librarian. Her first article for the paper heavily criticized Oberlin’s affirmative action program and received a “hugely negative response” from other students on campus. She graduated in 1992 and later described her alma mater as “radically left-wing”.

They married in 1993, and have two children. Jesse Malkin worked as an associate policy analyst and economist focusing on healthcare issues for the RAND Corporation. In 2004, Malkin reported on her website that her husband had left a “lucrative health-care consulting job” to be a stay-at-home dad. Jesse Malkin helps book his wife’s speaking engagements and helps her run her business.

Malkin began her journalism career at the Los Angeles Daily News, working as a columnist from 1992 to 1994. In 1995, she worked in Washington, D.C. as a journalism fellow at the Competitive Enterprise Institute, a free-market, anti-government regulation, libertarian think tank. In 1996, she moved to Seattle, Washington, where she wrote columns for The Seattle Times. Malkin became a nationally syndicated columnist with Creators Syndicate in 1999.

Malkin is a proponent of legalizing the medical use of cannabis, dating back to 1998 when she argued in favor of the passage of Washington State’s Initiative 692. She also criticized the war on drugs as a “dismal, costly, inefficient failure” in a 1997 column titled “Liberty Is Biggest Loser In Nation’s War On Drugs”. In a 2014 interview Malkin said she was “grateful” for the passage of Colorado’s Amendment 64 (legalizing recreational use), as it allowed her ailing mother-in-law to easily obtain cannabis.

In 2004, she wrote In Defense of Internment: The Case for ‘Racial Profiling’ in World War II and the War on Terror, defending the U.S. government’s internment of 112,000 Japanese Americans in prison camps during World War II, and arguing that the same procedures could be used on Arab- and Muslim-Americans today. The book engendered harsh criticism from several Asian American civil rights organizations. The Historians’ Committee for Fairness, an organization of scholars and professional researchers, condemned the book for not having undergone peer review and argued that its central thesis is false. As a result of the controversy, the Hawaii-based newspaper MidWeek dropped her column in August 2004; The Virginian-Pilot called her “an Asian Ann Coulter” and dropped her column in November 2004. Malkin responded: “I’m not Asian, I’m American”, and described the comparison to Coulter as “a compliment”.

In June 2004, Malkin launched a political blog, MichelleMalkin.com. A 2007 memo from the National Republican Senatorial Committee described Malkin as one of the five “best-read national conservative bloggers”, and as of 2012 Technorati had ranked MichelleMalkin.com in its “Top 100 blogs of all types”. In 2011, the people search company PeekYou claimed that Malkin had the largest digital footprint of any political blogger.

Malkin’s third book, Unhinged: Exposing Liberals Gone Wild, was released in October 2005.

On April 24, 2006, Hot Air, a “conservative Internet broadcast network”, went into operation, with Malkin as founder/CEO. The site’s staff at launch included Allahpundit and Bryan Preston. Preston was replaced by Ed Morrissey on February 25, 2008. In February 2010, Hotair.com was bought by Salem Communications and is no longer administered by Malkin.

Malkin was among the first of several bloggers who questioned the credibility and even the existence of Iraqi police Captain “Jamil Hussein” who had been used as a source by the Associated Press in over 60 stories about the Iraq war. The controversy started in November 2006 when the AP reported that six Iraqis had been burned alive as they left a mosque and that four mosques had been destroyed, citing Hussein as one of its sources. In January 2007, Malkin visited Baghdad, and stated, “the Iraqi Ministry of Interior says disputed Associated Press source Jamil Hussein does exist. At least one story he told the AP just doesn’t check out: The Sunni mosques that as Hussein claimed and AP reported as ‘destroyed,’ ‘torched’ and ‘burned and blown up’ are all still standing. So the credibility of every AP story relying on Jamil Hussein remains dubious.” Malkin has since issued a correction for her denial of Hussein’s existence, “I relayed information from multiple sources—CPATT, Centcom, and two other military sources on the ground in Iraq—that the Associated Press’s disputed source, Jamil Hussein, could not be found.” […] “I regret the error,” but still contested AP claims of destroyed mosques and civilians burned alive.

In April 2006, Students Against War (SAW), a campus group at University of California, Santa Cruz, staged a protest against the presence of military recruiters on campus, and sent out a press release containing contact details (names, phone numbers and e-mail addresses) of three student leaders for use by reporters. Malkin included these contact details in a blog column entitled “Seditious Santa Cruz vs. America”. Malkin claimed the contact information was originally taken from SAW’s own website, but that later SAW had removed it and had “wiped” the “cached version”. The students asked Malkin to remove the contact details from her blog, but Malkin reposted them several times writing in her blog: “I am leaving it up. If you are contacting them, I do not condone death threats or foul language. As for SAW, my message is this: You are responsible for your individual actions. Other individuals are responsible for theirs. Grow up and take responsibility.”

Another controversy involving private addresses began on July 1, 2006, when Malkin and other bloggers commented on a New York Times Travel section article that had featured the town where Vice President Dick Cheney and Secretary of Defense Donald Rumsfeld owned summer homes. The article included a picture of Rumsfeld’s long tree-lined driveway that showed a birdhouse and small portion of the housefront. Malkin declared that this story was part of “a concerted, organized effort to dig up and publicize the private home information of prominent conservatives in the media and blogosphere to intimidate them.” The photos of Rumsfeld’s house were taken with Rumsfeld’s permission.

In 2006, Malkin gave a lecture at her alma mater, Oberlin College, discussing racism, among other topics. She denied allegations that she had been insensitive to the “plight of minorities”, listing several racial epithets that had been used against her, and by relating a lesson she learned from her mother for which she is “eternally grateful”. When in kindergarten, Malkin went home in tears one day because her classmates had called her a racist name. But her mother comforted Michelle by telling her that everyone has prejudices.

For years, Malkin was a frequent commentator for Fox News and a regular guest host of The O’Reilly Factor. In 2007, she announced that she would not return to The O’Reilly Factor, claiming that Fox News had mishandled a dispute over derogatory statements made about her by Geraldo Rivera in a Boston Globe interview. Since 2007, she has concentrated on her writing, blogging, and public speaking, although she still appears on television occasionally, especially with Sean Hannity and formerly with Greta Van Susteren on Fox News and Fox & Friends once a week.

Malkin accused hip hop artist Akon of degrading women in a HotAir YouTube video in May 2007. Following this, Akon’s record label, Universal Music Group (UMG), issued a DMCA takedown notice removing the video. UMG retracted the notice after the Electronic Frontier Foundation joined Malkin in contesting the removal as a misuse of copyright law.

MichelleMalkin.com was revamped and moved to a larger server on WordPress in June 2007.

Culture of Corruption: Obama and His Team of Tax Cheats, Crooks, and Cronies, Malkin’s fourth book, was released in July 2009 and was a The New York Times Non-Fiction, Hardcover Best Seller for six weeks. Malkin said she hoped the book would “shatter completely the myths of hope and change in the new politics in Washington”, described the Obama administration as run by “influence peddlers, power brokers and very wealthy people”, and called it “one of the most corrupt administrations in recent memory”. She later discussed chapter two of the book, “Bitter Half: First Crony Michelle Obama”, on NBC’s Today show. She described Michelle Obama as “steeped in the politics of the Daley machine”, and as having based her professional career on nepotism and “old white boy” network connections.

During an appearance as a news analyst on the roundtable segment of ABC’s This Week with George Stephanopoulos on August 2, 2009, she explained why she opposed another 13-week extension of unemployment benefits: “If you put enough government cheese in front of people they are going to just keep eating it and kicking the can down the road… people will just delay getting a job until the three weeks before the benefits run out.”

Who Built That: Awe-Inspiring Stories of American Tinkerpreneurs, released May 2015, presents stories of American inventors and business people, directly challenging the “you didn’t build that” statement made by President Barack Obama on July 13, 2012.

Malkin had been a contributor to CRTV, but left the network following its merger with TheBlaze in December 2018 and joined competitor Newsmax TV.

In 2019, Malkin gave a speech at the Conservative Political Action Conference (CPAC) condemning politicians, including the “ghost” of recently deceased Senator John McCain, for failing to enact stricter immigration regulation.

In 2020, Malkin faced criticism for speaking at a conference hosted by far-right former YouTuber Nick Fuentes and Patrick Casey, head of the neo-Nazi organization known as the American Identity Movement (formerly Identity Evropa). At the conference, Malkin said it was “not anti-semitic” to question “whatever the precise number of people is who perished in World War II.” Malkin was dropped by the conservative YAF organization for her support of Fuentes, who has also denied the Holocaust.