DeHaan was born in Allentown, Pennsylvania. His father, Jeff, is a computer programmer, and his mother, Cynthia Boscia, is an executive at Metlife. He has an older sister, Meghann, and had what the New York Times Magazine has described as a "very normal, super-supportive childhood." He attended Emmaus High School in Emmaus, Pennsylvania, for three years and appeared in community theater. He switched to the University of North Carolina School of the Arts for his senior year of high school, where he was "around artists for the first time." He continued at UNCSA for undergraduate studies, graduating in 2008.\n', '
DeHaan got his start on stage as understudy for Haley Joel Osment in the short-lived Broadway revival of American Buffalo. In 2008, he made his television debut, guest-appearing on an episode of Law & Order Special Victims Unit, and his 2010 feature film debut in John Sayles\' Amigo. He played Jesse in the third season of In Treatment and played Timbo in the fourth season of True Blood.\n', '
In 2012, DeHaan starred in the camcorder drama film Chronicle, and as Cricket in Lawless. In 2013, he played Lucien Carr, a contemporary of Allen Ginsberg and Jack Kerouac, in Kill Your Darlings, alongside Daniel Radcliffe. It was a role for which he has received critical acclaim. He was the cover star of Hero magazine issue 10, shot by Hedi Slimane and published in October 2013. In 2014, Annie Leibovitz photographed DeHaan for a Prada clothing "men’s spring advertising campaign". Also that year, he played Harry Osborn, in The Amazing Spider-Man 2 and Zach Orfman in Life After Beth.\n', '