Gladwell's British father, Graham M. Gladwell, is a civil engineering professor emeritus at the University of Waterloo in Ontario, Canada; his mother, Joyce E. (née Nation), is a Jamaican-born psychotherapist. Gladwell was born in Fareham, Hampshire, England, but when he was six his family moved to Elmira, Ontario, Canada.According to research done by Professor Henry Louis Gates, Jr., of Harvard University, in 2010 for the PBS series Faces of America, Gladwell's family tree includes ancestors of West Indian, Igbo, Irish, English and Scottish heritage. One of his European ancestors, an Irishman named William Ford, arrived in Jamaica in the mid-17th century and with his concubine, an Igbo slave named Hannah Burton, he had a son named John Ford seeding a long line of privileged mixed-race Jamaicans, the Fords. On his father's side, his great-great grandparents, Thomas Adams and Jane Wilson, left England and Ireland to take part in the Castlemaine gold rush in Victoria, Australia in the 1850s. Gladwell has said that his mother, who published a book titled Brown Face, Big Master in 1969, is his role model as a writer.. His cousin is the American statesman Colin Powell

He graduated with a degree in history from the University of Toronto's Trinity College in 1984. During his high school years, Gladwell was an outstanding middle-distance runner and won the 1500 meter title at the 1978 Ontario High School championships in Kingston, Ontario, in a duel with eventual Canadian Open record holder David Reid. In the summer of 1982, Gladwell interned with the National Journalism Center in Washington, D.C.

Gladwell began his career at The American Spectator, a conservative monthly. He subsequently wrote for Insight on the News, a conservative magazine owned by the Rev. Sun Myung Moon's Unification Church, before joining The Washington Post as a business writer in 1987. He later served as a science writer and as New York bureau chief for the Post before leaving the paper in 1996. He is currently a staff writer for The New Yorker. His books...The Tipping Point (2000) and Blink (2005)...were international bestsellers. Both works were substantially serialized in The New Yorker. Gladwell received a US$1 million advance for The Tipping Point, which went on to sell over two million copies in the United States. Blink sold equally well. His third book, The Story of Success, was released November 18, 2008. His latest book, And Other Adventures, was published on October 20, 2009. What the Dog Saw bundles together his favorite articles from The New Yorker since he joined the magazine as a staff writer in 1996.

Gladwell's first work, The Tipping Point, discusses the potentially massive implications of small-scale social events, while his second book, Blink, explains how the human subconscious interprets events or cues and how past experiences allow people to make informed decisions very rapidly. Outliers examines how a person's environment, in conjunction with personal drive and motivation, affects his or her possibility and opportunity for success. Gladwell stated, "The hope with Tipping Point was it would help the reader understand that real change was possible. With Blink, I wanted to get people to take the enormous power of their intuition seriously. My wish with Outliers is that it makes us understand how much of a group project success is. When outliers become outliers it is not just because of their own efforts. It's because of the contributions of lots of different people and lots of different circumstances."

Gladwell's books and articles often deal with the unexpected implications of research in the social sciences and make frequent and extended use of academic work, particularly in the areas of psychology, and social psychology.