Park was born in Seongbuk-dong, Seongbuk-gu, Seoul, South Korea,[2][3] the youngest of three siblings, and raised in the United States, later becoming an American citizen.

[4] In 1997 Park moved to Seoul, South Korea, where his older sister had been working, with the dream of creating a pop music group.

[6][7][8] In the midst of preparations for the group's debut and album, Park was cast in a beer commercial for Oriental Brewery and also landed a small recurring role in the SBS sitcom Soonpoong Clinic (ko) as the boyfriend of Song Hye-kyo's character.

Park later stated that all his earnings from the commercial and sitcom was spent on daily living expenses during the period he and the other members did not receive financial funding from their agency for over a year.

[5] The final member, high school student Kim Tae-woo, joined the group in July 1998 after sending in an audition tape and impressing Park Jin-young during their meeting.

He moved back to the Los Angeles area to pursue acting, having a cameo on Speed Racer as the Platinum blond-haired Yakuza Driver and the role of Yamcha in the live-action film version of Dragonball Evolution in which he starred with Chow Yun Fat, Justin Chatwin, Emmy Rossum and Jamie Chung.

[21] He and fellow K-pop stars Sunny from Girls' Generation and Jackson Wang from Got7 joined the cast for the second season of Roommate, a reality television series in which various celebrities share a house and are responsible for all household chores and meals.

He also appeared in the music videos for "Shake That Brass", the title track of singer-rapper Amber Liu's debut EP Beautiful,[23] and "Hot Sugar" (뜨거운 설탕), the comeback single of Kim Jong-kook's group Turbo.

[24] In July 2018, Park opened a YouTube channel called Wassup Man featuring himself video blogging his travels in Korea.