Wente was born in Evanston, Illinois and moved to Don Mills, Ontario in 1964 when her mother married a Canadian. She has since become a naturalized Canadian citizen. She holds a BA in English from the University of Michigan and an MA in English from the University of Toronto. In 2004 Margaret Wente published Accidental Canadian, her autobiographical account of becoming a columnist at The Globe & Mail.
Though Wente did her undergraduate college studies in Ann Arbor, Michigan, every year from May through August she returned to Toronto to serve tables at The Coffee Mill, a Hungarian restaurant:
I schlepped espressos and salami sandwiches, oceans of goulash and mountains of pastries and gallons of orange frappes. [The Coffee Mill] offered a hint of continental sophistication in a city that was still hopelessly parochial….Some of the customers were genuine writers…In nice weather they could sit outdoors on a terrace…I was serving the intelligencia…I wore a white polyester apron with a miniskirt and high-heeled sandals. (p 41)
After graduating from University of Michigan, noticing that the USA was in a "dark phase, torn apart by the politics of Vietnam" (p 7), she chose to live and work in Canada.
Wente was "hired right out of university to be a book publicist" (p 20). Her first assignment was a book on the Summit Series, a confrontation in 1972 of national ice hockey teams from Canada and Russia. She did her job and spent time with the coach, but in her own memoir shows her opinion:
[Hockey] is a sport where they send their big star out to play after he’s had his seventh concussion. He says he's fine, but how would he know? His brain has turned to scrambled eggs. (p 23)
She claims "Hockey does not promote civic engagement. It destroys it" (p 24).
She joined The Globe and Mail in 1986. She has been editor of the paper's business section, the ROB [Report on Business], and managing editor of the paper. Her columns have appeared in the Globe and Mail since 1992, and she has been a full-time columnist for the paper since 1999. She is a frequent commentator on television and radio, and has won several journalism awards.
In September 2012, Wente was found to have committed plagiarism by Carol Wainio, a blogger and artist who accused Wente of lifting quotes and rewording passages from published sources without credit. Wainio documents on her blog, Media Culpa, a series of columns and articles published from 2009 to 2012, which plagiarize sources including the Ottawa Citizen, the New York Times and Foreign Affairs. On 21 September 2012, the Globe and Mail's public editor addressed the allegations, conceding that "there appears to be some truth to the accusations but not on every charge."
The Globe and Mail subsequently took unspecified punitive actions against Wente for a column written in 2009. Editor John Stackhouse acknowledged that "the journalism in this instance did not meet the standards of The Globe and Mail," noting that the work in question was "unacceptable." However, Wente continued to write for the Globe and Mail. Wente herself wrote a column to defend herself against accusations of being a "serial plagiarist" but acknowledged she was "extremely careless". She took a break from writing her column for a week. On 11 October she resumed with a column explaining her actions and offered an apology.
She was also suspended from CBC Radio where she appeared as a biweekly media panelist on the program Q due to her not meeting the CBC's journalistic standards as a result of the 2009 incident.
In 2016, the Globe and Mail confirmed two additional incidents of plagiarism by Wente. Editor-in-chief David Walmsley stated: “This work fell short of our standards, something that we apologize for. It shouldn’t have happened and the Opinion team will be working with Peggy to ensure this cannot happen again.”
In her Globe and Mail column, on Saturday, 1 March 2014, Wente criticized Canadian universities for their response to the Saint Mary's rape chant controversy, in particular their view that all drunken sex is rape. She went on to argue that rape culture is a fiction and that the concept of affirmative consent is part of the "war on men". Wente's column was subsequently referred to as "irresponsible nonsense" by fellow journalists Toula Drimonis and Ethan Cox.1975: "I Never Say Anything Provocative:" Witticisms, Anecdotes, and Reflections by Canada's Most Outspoken Politician, John G. Diefenbaker, Peter Martin Associates, ISBN 0-88778-132-2 . (Compiler and Editor)
2004: An Accidental Canadian: Reflections on My Home and (Not) Native Land, HarperCollins, ISBN 0-00-200798-3 .
2009: You Can't Say That in Canada, HarperCollins, ISBN 978-1-55468-468-7 .