Badgley was born in Baltimore, Maryland and split his childhood years between Richmond, Virginia and Seattle, Washington. In Seattle, he attended Charles Wright Academy (in Tacoma, WA), and was involved with the Seattle Children's Theatre. He soon began doing voice-overs for a children's radio stations.
At age 11, Badgley relocated with his mother to Hollywood and began pursuing an acting career. According to Badgley's former homeschool classmate Blake Lively, Badgley also pursued a singing career, and recorded a pop single in 1998. At the age of 14, Badgley took the California High School Proficiency Exam and began attending Santa Monica College. At 17, after completing two years of credits at Santa Monica College, he was accepted as a Junior at the University of Southern California (USC), where he deferred admission due to contractual obligations.
Badgley's first credit was voice work for the video game Mario Golf 64 in 1999 although he claims to have never played it himself. He followed this in 2000 with voice work on Mario Tennis 64. His first screen acting credit was on an episode of Will & Grace. He followed this up with appearances on shows such as Daddio, The Brothers Garcia and What I Like About You, among others.He also appears in John Tucker Must Die playing Scott Tucker. In its opening weekend, the film grossed a total of $14.3 million, ranking third in the U.S. box office results for that weekend. As of November 2, the film has grossed $41 million domestically.
Badgley's first notice came with his role as Phillip Chancellor IV #8 on the soap opera The Young and the Restless (2000 - 2001). He was nominated for a 2001 Young Artist Award for Best Performance in a Daytime Series for his work.
In 2002, he starred in the WB half-hour series Do Over. Badgley starred as Joel Larsen, a 34-year-old man, gets a second chance to get his life right, thanks to a freakish accident that catapults him back to 1980, as a 14-year-old.The show premiered on The WB Television Network, which is currently known as The CW. He appeared on the Tonight Show with Jay Leno as this show opened. The series was cancelled short of a full season. Badgley later apppeared in Drive-Thru playing Van co-starring future castmate Leighton Meester.
Wider audiences may recognize him from his next starring role as Sam Tunney in The Mountain (2004 - 2005), but was cancelled after the first season. The same thing happened to The Bedford Diaries, another series where Badgely had a lead role. While the show was popular, it was cancelled in its first season.
In The CW's new drama Gossip Girl, Badgley portrays Dan Humphrey, the son of 1990's former rock star Rufus Humphrey (Matthew Settle). He plays the love interest of Upper East Side's it girl, Serena van der Woodsen (Blake Lively). The show revolves around the lives of socialite young adults growing up on New York's Upper East Side who attend elite academic institutions while dealing with sex, drugs, and other teenage issues.
He is set to star in the announced 2008 remake of the 1987 American thriller film The Stepfather.
In late 2007, it was reported that Badgley was dating his Gossip Girl co-star and former childhood classmate Blake Lively. In May 2008, People magazine published photos of Lively and Badgley kissing while on vacation in Mexico. The two have since become more open about their relationship.
In October 2008, Badgley appeared alongside Lively in a MoveOn.org campaign ad in support of Presidential candidate Barack Obama.
