Jung Woo Seok (정우석) is the main rapper, vocalist, and maknae of the boy group Pentagon under Cube Entertainment. Wooseok often grabs attention for being the Tallest in the group, and for having a deep voice. Moreover, Wooseok has collaborated with many artists such as Soyeon of (G)I-DLE and Lai Kuanlin.
He debuted as the maknae of PENTAGON on October 10, 2016 with the mini album "PENTAGON".
On February 22, 2019, Cube Entertainment announced that Wooseok would be debuting in a new unit project alongside labelmate and former Wanna One member Lai Kuan-lin. The unit, Wooseok X Kuanlin, made their debut on March 11, 2019 with the title track "I'm A Star" and debut extended play, 9801.
In October, Wooseok was confirmed as a contestant on the rap competition program Show Me The Money 9. During the 60 Second Team Trials, he received one pass and three fails from the producers, and was subsequently eliminated from the show.