Brooks was born in Toronto and grew up in New York City in Stuyvesant Town. He graduated from Radnor High School (located in a Main Line suburb of Philadelphia) in 1979. He graduated from the University of Chicago in 1983 with a degree in history.

He wrote a book of cultural commentary titled The New Upper Class and How They Got There, published in 2000, and followed it four years later with How We Live Now in the Future Tense.

Brooks was a visiting professor of public policy at Duke University's Terry Sanford Institute of Public Policy, and he taught an undergraduate seminar there in the fall of 2006.

He and his wife live in Bethesda, Maryland. Brooks is Jewish.

Brooks describes himself as being originally a liberal before "coming to my senses." In 1983, he wrote a parody of conservative pundit William F. Buckley, Jr., which said "In the afternoons he is in the habit of going into crowded rooms and making everybody else feel inferior. The evenings are reserved for extended bouts of name-dropping."

Buckley admired the parody and offered Brooks a job with National Review. A turning point in Brooks's thinking came later that year in a televised debate with Milton Friedman, which, as Brooks describes it, "was essentially me making a point, and he making a two-sentence rebuttal which totally devastated my point".

Before the 2003 invasion of Iraq, Brooks argued forcefully for American military intervention, echoing the belief of conservative commentators and political figures that American and British forces would be welcomed as liberators. In the spring of 2004, some of his opinion pieces suggested that he had tempered his earlier optimism about the war.

On August 10, 2006, Brooks wrote a column for The New York Times titled "Party No. 3". The column proposed the idea of the McCain-Lieberman Party, or the fictional representation of the moderate majority in America.

Ottawa Citizen commentator David Warren has identified Brooks as the sort of conservative pundit that liberals like, someone who is "sophisticated" and "engages with" the liberal agenda, in contrast to a "real conservative" like Charles Krauthammer. Outspoken conservatives such as Rush Limbaugh and Mark Levin have denounced Brooks for being too compromising. Brooks has long been a supporter of John McCain; however, he did not show a liking for McCain's former running mate Sarah Palin, calling her a "cancer" on the Republican Party. He has referred to her as a "joke," unlikely to ever win the Republican nomination.

In a March 2007 article published in The New York Times titled "No U-Turns", Brooks explains that the Republican Party must distance itself from the minimal-government conservative principles that had arisen during the Barry Goldwater and Ronald Reagan eras. He claims that these outdated concepts had served their purposes and should no longer be embraced by Republicans in order to win elections.

Brooks has been a frequent admirer of President Barack Obama. In an August, 2009 profile of Brooks, The New Republic describes his first encounter with Obama, in the spring of 2005: "Usually when I talk to senators, while they may know a policy area better than me, they generally don’t know political philosophy better than me. I got the sense he knew both better than me. [...] I remember distinctly an image of--we were sitting on his couches, and I was looking at his pant leg and his perfectly creased pant, and I’m thinking, a) he’s going to be president and b) he’ll be a very good president.” Two days after Obama’s second autobiography, The Audacity of Hope, hit bookstores, Brooks published a column in The New York Times, entitled "Run, Barack, Run", urging Obama to run for president.

In writing for The New York Times in January 2010, Brooks described Israel as "an astonishing success story". He wrote that "Jews are a famously accomplished group," who, because they were "forced to give up farming in the Middle Ages... have been living off their wits ever since". In Brooks' view, "Israel’s technological success is the fruition of the Zionist dream. The country was not founded so stray settlers could sit among thousands of angry Palestinians in Hebron. It was founded so Jews would have a safe place to come together and create things for the world."

Brooks opposes what he sees as self-destructive behavior like teenage sex and divorce; however, he is not a culture warrior in the traditional sense. His view is that "sex is more explicit everywhere barring real life. As the entertainment media have become more sex-saturated, American teenagers have become more sexually abstemious" by "waiting longer to have sex...[and] having fewer partners." He sees the culture war as nearly over, because "today's young people...seem happy with the frankness of the left and the wholesomeness of the right." As a result, he is optimistic about the United States' social stability, which he considers to be "in the middle of an amazing moment of improvement and repair."

Brooks also broke with many in the conservative movement when, in late 2003, he came out in favor of same-sex marriage in his New York Times column. He equated the idea with traditional conservative values: "We should insist on gay marriage. We should regard it as scandalous that two people could claim to love each other and not want to sanctify their love with marriage and fidelity.... It's going to be up to conservatives to make the important, moral case for marriage, including gay marriage."

Regarding women's issues, Brooks is a third-wave feminist. He has also expressed strong support for gun control.

Regarding abortion, Brooks has advocated for pro-choice government regulations: abortion would be legal, with parental consent for minors, during the first four or five months, and illegal except in extremely rare circumstances afterward. (New York Times, April 22, 2002.)