After their unofficial breakup in 2002, Ock released three solo albums and has participated in musicals, namely Wicked, Aida, Chicago, Cats, 42nd Street, and The Count of Monte Cristo.

Ock served as the lead singer for Fin.K.L until it became inactive as a group in 2002; she has since taken part in Fin.K.L's digital single "Fine Killing Liberty" in fall of 2005, including filming the music video.

Starting her solo career summer in 2003, Ock came out with a ballad called "난..." ("Nan...", meaning "I..."), which entered the top 10 of Korean music charts.

By her second album, which came out late fall in 2004, the public was startled by the sudden change in appearance, as she had experienced a significant weight loss; Ock attributed to her intense yoga training.

She was voted first place for her rendition of "1000 days", and also sang Korean ballad "Love is Gone", "Man is Ship, Woman is Harbor" and a re-make of fellow Fin.K.L member Lee Hyori's "U-Go Girl".

Playing a slightly unhinged and dark character, Ock showed a new side of herself and was rewarded with great popularity among audiences and received the 2013 Korean Musical Award for Best Actress in a supporting role.

[8] In 2014, Ock starred as Elphaba in the first Korean production of "Wicked the Musical"[9] and also reprises the role of Danvers in "Rebecca" due to its popularity in South Korea.

[11] He had stated that she had been one of the main inspirations for the character and songs of Mata Hari,[12] and had sung high praises of her performances in his other musicals such as The Count of Monte Cristo.

She appeared at the curtain call for opening night, and sang a trio with Ekaterina Guseva (Anna Karenina) and Sergey Lee (Alexey Vronsky).

[14] In February 2022, OCK has decided not to renew the contract with Potluck Co., Ltd.[15] * Note: Most, if not all, large scale South Korean Musicals are generally double or triple cast for a role.

2016.11.11 Ock Joo-hyun is a playable character in the video game Tony Hawk's Pro Skater 2 (only in the South Korean PC version).