Park began to attract attention with supporting roles in SBS' Three Days (2014), Six Flying Dragons (2015–2016) and Don't Dare to Dream (2016).

Park is better known in recent years for his villainous roles in the dramas The Glory (2022–2023) and Queen of Tears (2024), as well as playing the transgender ex-soldier Cho Hyun-ju in Squid Game season 2 (2024).

[6][7][8] At the age of 20, he took on his first lead role in a school class workshop, portraying Deokbae in the play titled Taxi Driver, written by director Jang Jin.

It was only later when he heard seniors describe the feeling of performing and receiving applause as akin to taking drugs that he realized the allure of the stage.

He had to work part-time until late at night, sleep in the theater, and couldn't secure a role due to teachers and senior actors receiving priority.

[3][12] Following his departure from the theater company, Park secured minor roles in the films A Frozen Flower (2008) and Jeon Woo-chi: The Taoist Wizard (2009).

he appeared as Yu Deok-hwa, the high school classmate of the main character Lee Seon-nam (played by Shim Hyung-tak).

Producer Ahn Hyeok-won invited him and Park's decision to participate as a guest was influenced by his agency mates, Jin Seon-kyu and Lee Hee-joon, who were members of Ganda.

In the fifth episode titled "They Fell", Park appeared as Chad opposite Yoon Na-moo as Randy, with whom he had previously worked in the play Model Students.

[19] In 2014, Park appeared as a communications team leader in SBS drama Three Days and gained great experience by working with talented seniors.

Park Jae-hyun, who underwent a heart transplant after a car accident in his youth, falls deeply in love with Seo-kyung.

Melodrama premiered in 2007 and received positive reviews for its artistic value and exploration of adultery, conveying a message about the true essence of love.

In 2015, Park, along with Kang Ki-dung, was double cast as the character of Myeong-jun, who had a false sense of inferiority hidden beneath his composed demeanor.

[26] The central theme of the play focused on the social struggles faced by marginalized groups, particularly sexual minorities: Philip, Oliver, Peter, and Sylvia, who lived in two different time periods—1958 and the present day.

The production, under the direction of Jamie Lloyd, also received a Laurence Olivier Award for Outstanding Achievement in an affiliate theatre.

Park expressed that after working on heavy projects consecutively, he wanted to do a comedy, and University of Laughs provided him with that opportunity.

The documentary was about the story of Kim Bok-dong, a comfort woman who traveled around the world demanding an apology from Japan and had fought until the end despite being over 90 years old.

Based on a true story, the film delves into the life of Sejong the Great (Han Suk-kyu), the king of the Joseon dynasty in Korea, and his relationship with his most brilliant scientist, Jang Yeong-sil (Choi Min-sik).

The series also starred Yoo Da-in, Han Joon-woo and Ahn Nae-sang,[49] aired on KBS2 every Wednesday and Thursday at 21:30 (KST) from July 1 to August 20, 2020.

[50][51] Park's portrayal of Seo Gong-myung in the show received praise for his on-screen chemistry with Nana, leading to them being referred to as the 'La Cong Couple.'

Additionally, Park showcased his singing abilities by releasing his first soundtrack, "Our Memories in Summer" (우리의 여름처럼), which featured Nana as well.

[53] In 2021, Park took on the lead role of Grand Prince Yangnyeong in the SBS Monday-Tuesday drama Joseon Exorcist, which premiered on March 22, 2021.

Notably, "The Distributors" marked a reunion for Park with director Hong Seok-gu, who had previously collaborated with him on KBS weekend drama My Only One.

Park starred alongside Song Hye-kyo, Lee Do-hyun, Lim Ji-yeon, Yeom Hye-ran, and Jung Sung-il.

[55] Park's character, Jeon Jae-joon, was a color-blind heir of a country club and was involved in the mistreatment of Dong-Eun (Song Hye-kyo).

[76] In January 2024, Park had made a special appearance in episodes 1-2 of the Netflix series The Bequeathed, which had been created and written by director Yeon Sang-ho.

[80] Queen of Tears reached a nationwide rating of 24.850% for its final episode and became the highest-rated tvN series, surpassing Crash Landing on You.

Some argued in response to this criticism that South Korea is conservative with regards to LGBTQ rights, and that trying to find a transgender actress willing to put herself in the spotlight was not reasonable.

[91] On December 30, 2024, Park faced controversy for accidentally posting a Japanese adult video cover parodying Squid Game on his Instagram story.

[92] Though there was speculation that his account was hacked, his agency confirmed that Park was responsible for sharing the photo, explaining that he had received it in a DM and meant to forward it to a company representative.