Park Yoo-chun was born on June 4, 1986 in Seoul, South Korea to a wealthy family. His family moved to the United States in 1998. He lived in Fairfax, Virginia, where he attended Holmes Middle School, Rocky Run Middle School, and Chantilly High School. Later his parents divorced.

From 2003 to 2009, Park performed as a member of the best-selling K-pop boy band TVXQ. In July 2009, Park and two of his TVXQ bandmates, Jaejoong and Junsu, filed a lawsuit against their South Korean agency S.M. Entertainment. Through their lawyers, the members stated that the 13-year contract was excessively long, schedules were held out without the confirmation or permission of the members, contract terms have been extended and changed without their knowledge or consent and that the group's earnings were not fairly distributed to the members. After TVXQ's Japanese label announced a group hiatus in early 2010, they formed a new three member group initially known as JUNSU/JAEJOONG/YUCHUN in Japan.

Park has written and composed several songs that have appeared on TVXQ's Korean and Japanese albums. As a member of SM Town, he contributed to the 2007 winter album Only Love with his composition "Evergreen". Park also wrote and composed "사랑 안녕 사랑 (Love Bye Love)", featured on the group's fourth Korean studio album Mirotic. For the Trick project, he wrote the lyrics to his solo "My Girlfriend", entirely in English.

Two months later, Park made his Korean debut as an actor in the hit 2010 KBS drama Sungkyunkwan Scandal (성균관스캔들). He portrayed Lee Seon Joon, a wealthy, passionable and studious nobleman, who falls in love with his fellow schoolmate—a woman disguised as a man. He received the "Rookie of the Year" Award, "Netizen Award" and "Best Couple" Award at the 2010 KBS Drama Awards ceremony. He won "Best Newcomer Award" and "Most Popular Actor in a TV Drama" at The 47th Baeksang Arts Awards, the most prestigious entertainment awards in South Korea. Park also won "Best Actor" and "Most Popular Asian Actor" at the 6th Seoul International Drama Awards.

In 2011, he starred in the MBC drama Miss Ripley with Lee Da-hae, Kim Seung-woo, and Kang Hye-jung. His character as Song Yoo-hyun has him playing a half-Korean, half-Japanese second-generation Director who will falls blindly in love with the antiheroine. At the 2011 MBC Drama Awards, Park won "Best Newcomer" for his role as lead male in "Miss Ripley."

Having played the main character in a SBS and a MBC drama during 2012, Park attended both networks' drama award shows. At the MBC Drama Awards on December 30, the actor won the "Excellence Actor in a Mini-Series" Award for his role in Missing You. At the SBS Drama Awards the following day on the 31st, he received four more awards--"Excellence Actor in a Drama Special", one of the "Top 10 Stars", "Best Couple" (shared with Han Ji-min), and the "Netizen Popularity" Award—at the SBS Drama Awards for his performance in popular drama Rooftop Prince.

In 2014 and 2015 he won the title of "Best New Actor" for his performance in Haemoo at numerous entertainment awards, including the Baeksang Arts Awards, the Blue Dragon Awards, the Daejong Film Awards, the Busan International Film Festival and the SACF Beautiful Artists Awards.

In April 2017, it was confirmed by Park's agency that he will be marrying Hwang Ha-na, granddaughter of Namyang Dairy Products Company, in the fall. However, their wedding was postponed twice.

On January 17, 2018, Park was sued by an acquaintance for 1.2 billion won for the charge of negligence resulting in injury caused by a dog bite that occurred seven years prior.