Tapper was born in New York City and was raised in Queen Village in Philadelphia . He is the son of Theodore S. "Ted" and Helen Anne (nee Palmatier) Tapper.

Tapper is the author of The Outpost: An Untold Story of American Valor, a critically acclaimed book about U.S. troops in Afghanistan that debuted at number 10 on The New York Times bestseller list for hardback non-fiction. Bob Woodward described the book as: "Brilliant, dedicated reporting by a journalist who goes to ground to get the truth. A sad, real tale about this war, America and the brave warriors who live--and die--at the point of the spear" and Jon Krakauer called it "a mind-boggling, all-too-true story of heroism, hubris, failed strategy, and heartbreaking sacrifice. If you want to understand how the war in Afghanistan went off the rails, you need to read this book." In 2014, the Congressional Medal of Honor Society recognized Tapper for the book and his reporting on military topics in general with the Tex McCrary Award for Excellence in Journalism. In addition to The Outpost, Tapper is the author of Down and Dirty: The Plot to Steal the Presidency, based on the 2000 Presidential election, that The Washington Post called "lively", the Chicago Tribune "a churning effusion well worth reading" and The Daily Telegraph "engrossing". He also wrote Body Slam: The Jesse Ventura Story (St. Martin's Press) that was excerpted by The Washington Post Magazine. Tapper also wrote a political thriller entitled The Hellfire Club released in 2018. The novel follows a new congressmen discovering corruption and conspiracy in 1950s Washington. His comic strip Capitol Hell appeared in Roll Call from 1994 to 2003. He has also contributed cartoons to The American Spectator magazine, the Los Angeles Times, and The Philadelphia Inquirer. During the week of May 23, 2016, Tapper guest illustrated the Dilbert cartoon. The original drawings were auctioned online to raise money for the Homes for our Troops Foundation.

Did he win any awards for this book?
In 2014, the Congressional Medal of Honor Society recognized Tapper for the book and his reporting on military topics in general with the Tex McCrary Award for Excellence in Journalism.