Steyn was born in Toronto. He was baptized a Catholic and later confirmed in the Anglican Church; he has stated that "the last Jewish female in my line was one of my paternal great-grandmothers" and that "both my grandmothers were Catholic". Steyn's great-aunt was artist Stella Steyn. Steyn was educated at the King Edward's School, Birmingham, in the United Kingdom. He left school in 1978 at 18 and worked as a disc-jockey before becoming musical theatre critic at the newly established The Independent in 1986. He was appointed film critic for The Spectator in 1992. After writing predominantly about the arts, Steyn's focus shifted to political commentary and moved to the conservative broadsheet The Daily Telegraph which stopped carrying his column in 2006.

Since then, he has written for a wide range of publications, including the Jerusalem Post, The Orange County Register, Chicago Sun-Times, National Review, The New York Sun, The Australian, Macleans, Irish Times, National Post, The Atlantic Monthly, Western Standard and New Criterion.

Steyn's website provides special commentary and access to many of his columns and other published work. He occasionally posts to the National Review Online group blog, The Corner.

Steyn's books include Broadway Babies Say Goodnight: Musicals Then and Now (a history of the musical theatre) and America Alone: The End of the World as We Know It, a New York Times bestseller. He has also published collections of his columns and his celebrity obituaries and profiles from The Atlantic.

Steyn occasionally fills in for Rush Limbaugh, a conservative talk show radio host.

Steyn is a visiting professor at Hillsdale College.

Steyn's writing draws supporters and detractors for content. His style was described by Robert Fulford as "bring[ing] to public affairs the dark comedy developed in the Theatre of the Absurd."Longtime editor and admirer Fulford also wrote, "Steyn, a self-styled 'right-wing bastard,' violates everyone's sense of good taste." According to Simon Mann, Steyn "gives succour to the maxim the pen is mightier than the sword, though he is not averse to employing the former to advocate use of the latter."

Susan Catto in Time noted his interest in controversy, "Instead of shying away from the appearance of conflict, Steyn positively revels in it."Canadian journalist Steve Burgess wrote "Steyn wields his rhetorical rapier with genuine skill" and that national disasters tended to cause Steyn "to display his inner wingnut."

Criticism of media

Steyn frequently criticizes the institutional media.

In a May 2004 column Steyn commented that editors were encouraging anti-Bush sentiments after The Daily Mirror and the Boston Globe had published faked pictures, originating from American and Hungarian pornographic websites,of British and American soldiers purportedly sexually abusing Iraqis.Steyn argues that media only wanted to show images to westerners "that will shame and demoralize them."

In a July 2005 column for National Review, Steyn criticized Andrew Jaspan, then the editor of The Age, an Australian newspaper. Jaspan was offended by Douglas Wood, an Australian kidnapped and held hostage in Iraq, who after his rescue referred to his captors as "arseholes." Jaspan claimed that "the issue is really largely, speaking as I understand it, he was treated well there. He says he was fed every day, and as such to turn around and use that kind of language I think is just insensitive." Steyn argued that there is nothing at all wrong with insensitivity toward murderous captors, and that it was Jaspan, not Wood, who suffered from Stockholm syndrome. He said further, "A blindfolded Mr. Wood had to listen to his captors murder two of his colleagues a few inches away, but how crude and boorish would one have to be to hold that against one's hosts?"

Conrad Black trial

Steyn wrote articles and maintained a blogfor Maclean's covering the 2007 business fraud trial of his friend Conrad Black in Chicago, from the point of view of one who was never convinced Black committed any crime. Doing this, he later wrote, "cost me my gig at the [Chicago] Sun-Times" and "took me away from more lucrative duties such as book promotion".Steyn expressed dismay at "the procedural advantages the prosecution enjoys ... the inducements it's able to dangle in order to turn witnesses that, if offered by the defence, would be regarded as the suborning of perjury; or the confiscation of assets intended to prevent an accused person from being able to mount a defence; or the piling on of multiple charges which virtually guarantees that a jury will seek to demonstrate its balanced judgment by convicting on something. All that speaks very poorly for the federal justice system."

After Black's conviction, Steyn published a long essay in Maclean's about the case, strongly criticizing Black's defense team.

Eurabia

Steyn believes that Eurabia — a future where the European continent is dominated by Islam — is an imminent reality that cannot be reversed. "The problem, after all, is not that the sons of Allah are 'long shots' but that they're certainties. Every Continental under the age of 40 — make that 60, if not 75 — is all but guaranteed to end his days living in an Islamified Europe.""Native populations on the continent are aging and fading and being supplanted remorselessly by a young Muslim demographic."Steyn claims that Muslims will account for perhaps 40 percent of the population by 2020, but Globe and Mail correspondent Doug Saunders labels the assertion false:

Slightly more than 4 percent of Europe's population is Muslim, as defined by demographers (though about 80 per cent of these people are not religiously observant, so they are better defined as secular citizens who have escaped religious nations).

It is possible, though not certain, that this number could rise to 6 percent by 2020. If current immigration and birth rates remain the same, it could even rise to 10 percent within 100 years.

But it won't, because Muslims don't actually have more babies than other populations do under the same circumstances. The declining population growth rates are not confined to native populations. In fact, immigrants from Muslim countries are experiencing a faster drop in reproduction rates than the larger European population.

In his book America Alone, Steyn posits that Muslim population growth has already contributed to a modern European genocide:

Why did Bosnia collapse into the worst slaughter in Europe since the second World War? In the thirty years before the meltdown, Bosnian Serbs had declined from 43 percent to 31 percent of the population, while Bosnian Muslims had increased from 26 percent to 44 percent. In a democratic age, you can't buck demography — except through civil war. The Serbs figured that out, as other Continentals will in the years ahead: if you cannot outbreed the enemy, cull 'em. The problem that Europe faces is that Bosnia's demographic profile is now the model for the entire continent.

When some left-wing critics claimed Steyn was advocating genocide in this passage, he wrote:

My book isn't about what I want to happen but what I think will happen. Given Fascism, Communism and ethnic cleansing in the Balkans, it's not hard to foresee that the neo-nationalist resurgence already under way in parts of Europe will at some point take a violent form. ... I think any descent into neo-Fascism will be ineffectual and therefore merely a temporary blip in the remorseless transformation of the Continent.

Criticism of multiculturalism

Steyn has commented on divisions between the Western world and the Islamic World. He criticizes the tolerance of what he calls "Islamic cultural intolerance." Steyn explains that multiculturalism only requires feeling good about other cultures and is "fundamentally a fraud ... subliminally accepted on that basis."In Jewish World Review, Steyn argues "Multiculturalism means that the worst attributes of Muslim culture — the subjugation of women — combine with the worst attributes of Western culture — licence and self-gratification." He states, "I am not a racist, only a culturist. I believe Western culture — rule of law, universal suffrage — is preferable to Arab culture."

After Steyn ridiculed Ayatollah Khomeni for giving advice on child abuse and bestiality,some Canadian leftists accused Steyn of concocting his facts, leading Steyn to pen a memorable refutation.

Christopher Hitchens on America Alone

In an essay about America Alone,Christopher Hitchens wrote that "Mark Steyn believes that demography is destiny, and he makes an immensely convincing case," then went on to detail many points at which he disagrees with Steyn.For instance, Hitchens believes that Steyn errs by "considering European Muslim populations as one. Islam is as fissile as any other religion, and considerable friction exists among immigrant Muslim groups in many European countries. Moreover, many Muslims actually have come to Europe for the advertised purposes; seeking asylum and to build a better life."

Nevertheless, Hitchens expressed strong agreement with some of Steyn's points, calling the book "admirably tough-minded."

Support of Iraq invasion

Steyn was an early proponent of the 2003 invasion of Iraq. In 2007 he reiterated his support while attacking Democrat John Murtha, stating that his plan for military action in Iraq was designed "to deny the president the possibility of victory while making sure Democrats don't have to share the blame for the defeat. ... [Murtha] doesn't support them in the mission, but he'd like them to continue failing at it for a couple more years".

The Canadian Jewish Congress Affair

In the course of a 2010 column for Maclean's,Steyn accused the Canadian Jewish Congress, which he often criticizes, of supporting what he called the "ubiquitous campus Judenhass" and a user of the term "kikeroaches" while criticising Ann Coulter, whom he called "a great defender of the state of Israel". He quoted criticism of Coulter from a page on the CJC's websitenot realizing it was a copy of an editorialfrom a small Toronto-area newspaper. Maclean's later appended a note to Steyn's column noting that

In this column, [...] quotes were attributed to the Canadian Jewish Congress that came from The Mississauga News. [...] Subsequent commentary and satire in the column was linked to those quotes. Maclean’s regrets any confusion they might have caused by attributing certain positions directly to the CJC.

In a subsequent Maclean's column,Steyn accused CJC head Bernie Farber of lying about details of the page on the CJC's website, called him "a Jewish book burner", and noted that "the only words even hinting that the unsigned editorial does not come from Bernie Farber’s desk were two small words in parentheses: '(Mississauga News)'". Steyn also claimed that "simply as a point of Canadian law, the CJC is the publisher", a claim which Chris Selley of the National Post called "astoundingly disingenuous", while accepting Steyn's argument "that he misinterpreted the words 'Mississauga News' as 'news from Mississauga that's relevant to the CJC,' rather than as an attribution."

In 2007, a complaint was filed with the Ontario Human Rights Commission related to an article "The Future Belongs to Islam,"written by Mark Steyn, published in Maclean's magazine. The complainants alleged that the article and Maclean's refusal to provide space for a rebuttal violated their human rights. The complainants also claimed that the article was one of twenty-two (22) Maclean's articles, many written by Steyn, about Muslims.

[http://www.ohrc.on.ca/en/resources/news/statement Statement] on Decision in Maclean's Cases, [[Ontario Human Rights Commission]]. April 9, 2008

Further complaints were filed with the Canadian Human Rights Commission and the British Columbia Human Rights Tribunal.

The Ontario Human Rights Commission refused in April 2008 to proceed, saying it lacked jurisdiction to deal with magazine content. However, the Commission stated that it, "strongly condemns the Islamophobic portrayal of Muslims ... Media has a responsibility to engage in fair and unbiased journalism."Critics of the Commission claimed that Maclean's and Steyn had been found guilty without a hearing. John Martin of The Province wrote, "There was no hearing, no evidence presented and no opportunity to offer a defence — just a pronouncement of wrongdoing."The OHRC defended its right to comment by stating, "Like racial profiling and other types of discrimination, ascribing the behaviour of individuals to a group damages everyone in that group. We have always spoken out on such issues. Maclean's and its writers are free to express their opinions. The OHRC is mandated to express what it sees as unfair and harmful comment or conduct that may lead to discrimination."

Steyn subsequently criticized the Commission, commenting that "Even though they (the OHRC) don't have the guts to hear the case, they might as well find us guilty. Ingenious!"

Soon afterwards, the head of the Canadian Human Rights Commission issued a public letter to the editor of Maclean's magazine. In it, Jennifer Lynch said, "Mr. Steyn would have us believe that words, however hateful, should be give . History has shown us that hateful words sometimes lead to hurtful actions that undermine freedom and have led to unspeakable crimes. That is why Canada and most other democracies have enacted legislation to place reasonable limits on the expression of hatred."The National Post subsequently defended Steyn and sharply criticized Lynch, stating that Lynch has "no clear understanding of free speech or the value of protecting it" and that "No human right is more basic than freedom of expression, not even the "right" to live one's life free from offence by remarks about one's ethnicity, gender, culture or orientation."

The federal Canadian Human Rights Commission dismissed the Canadian Islamic Congress' complaint against Maclean's in June 2008. The CHRC's ruling said of the article that, "the writing is polemical, colourful and emphatic, and was obviously calculated to excite discussion and even offend certain readers, Muslim and non-Muslim alike." However, the Commission ruled that overall, "the views expressed in the Steyn article, when considered as a whole and in context, are not of an extreme nature, as defined by the Supreme Court."

Steyn later wrote a lengthy reflection of his turmoil with the commissions and the tribunals. The reflection appears as the introduction to The Tyranny of Nice,a book authored by Kathy Shaidle and Pete Vere on Canada's human rights commissions. In it, Steyn writes:

I've learned a lot of lessons during my time in the crosshairs of the [Canadian human rights investigator Jennifer] Lynch mob. Although the feistier columnists have spoken out on this issue, the broad mass of Canadian media seems generally indifferent to a power grab that explicitly threatens to reduce them to a maple-flavoured variant of Pravda. One boneheaded "journalism professor" even attempted to intervene in the British Columbia trial on the side of the censors. As some leftie website put it, "Defending freedom of speech for jerks means defending jerks." Well, yes. But, in this case, not defending the jerks means not defending freedom of speech for yourself. It's not a left/right thing; it's a free/unfree thing. But an alarming proportion of the Dominion's "media workers" seem relatively relaxed about playing the role of eunuchs to the Trudeaupian sultans.

Mark Steyn was awarded the 2006 Eric Breindel Award for Excellence in Opinion Journalism for writing which "best reflects love of this country and its democratic institutions".The announcement quotes from Steyn's syndicated column for 26 June 2006, "Be Glad the Flag Is Worth Burning":

One of the big lessons of these last four years is that many, many beneficiaries of Western civilization loathe that civilization, and the media are generally inclined to blur the extent of that loathing.

Roger Ailes of Fox News presented the prize, which included a check for $20,000.

In 2010, Steyn was presented the Sappho Award from the International Free Press Society in Copenhagen, Denmark.