In 1996, Wahl began his career working with the Miami Herald as an intern. From there, he joined Sports Illustrated in November 1996. By October 2000, he was promoted to the position of senior writer. Wahl mostly covers college basketball and soccer for both the magazine and SI.com.

In his career, he has reported on 12 NCAA basketball tournaments, five World Cups, and three Olympic games.

He first gained critical acclaim for his 1998 cover story Where's Daddy?, which documented the growing number of illegitimate children born to professional athletes. Since then, he has written numerous cover stories and profiles on athletes. In addition, Wahl has received four Magazine Story of the Year awards given by the U.S. Basketball Writers Association.

Wahl’s wrote his first book in 2009 called The Beckham Experiment. The book was a New York Times Best Seller.

Wahl was born in 1974 in Mission, Kansas. He attended Princeton University where earned a Bachelor of Arts in Politics in 1996.Wahl is married to wife, Celine.