Although Hoon had no early experience in either modelling or acting, he made his debut in the latter with the role of Ah Da-mo in the South Korean TV series ‘New Tales of Gisaeng’, which also happened to be his breakthrough role. The series aired on SBS for 52 episodes starting from January 23, 2011 to July 17, 2011.
His portrayal as a supercilious second-generation chaebol in ‘New Tales of Gisaeng’ shot him to limelight and garnered him the New Star Award at the 20th SBS Drama Awards in 2011.
He then landed up with his first Chinese drama titled ‘The Bodyguard’ in 2012 essaying the role of Guo Xu, a security chief. The series was aired in ‘China Central Television’ (formerly Beijing Television) commonly called CCTV network.
The South Korean television drama ‘Faith’ that aired on SBS for 24 episodes from August 13, 2012, to October 30, 2012, saw him playing the nefarious and shady character of Chun Eum-ja who carries a deadly flute. The other series he featured that year, also aired in SBS, was ‘The Birth of a Family’ where he played an entrepreneur Han Ji-hoon.
The next lead character he portrayed was that of a handsome and rich chaebol Kang Moo Yool in the South Korean weekend TV drama series ‘Passionate Love’ that aired on SBS for 47 episodes from September 28, 2013 to March 23, 2014.
In 2014 he also featured as Min-soo in the web drama ‘6 Persons Room’. His character was that of a thriving entrepreneur and womaniser who suddenly finds himself in the middle of strange patients after being hospitalised due to an injury.
His role as chaebol Lee Kang Hoon in the 2015 South Korean web series ‘Noble, My Love’ only upped his popularity. The series showed how the life of his character, a CEO of Korean branch of world’s biggest corporation D.O.L, changes after a chance encounter with Cha Yoon Seo, a veterinarian played by Kim Jae Kyung.
He essayed the role of pro-boxer Jang Joon-sung AKA "Korean Snake" in the rom-com drama TV series ‘Oh My Venus’ that aired on KBS2 for 16 episodes starting from November 16, 2015 to January 5, 2016. His character was shown as an orphan who was guided and trained to become a pro-boxer by personal trainer of Hollywood stars in America John Kim played by So Ji-sub.
A gifted Disc jockey, Hoon performs in such capacity under stage name ROI. He has showcased his talent in the field performing in several countries in June 2015 which includes Thailand, Singapore, Hong Kong, Indonesia and Malaysia.
Starting from February 20, 2016 to August 21, 2016, he starred as Kim Sang-min in the South Korea weekend drama television series ‘Five Enough’ that aired on KBS2. His portrayal as model turned professional golfer Kim Sang-min earned him the Best New Actor award at the 30th KBS Drama Awards in 2016.
He made his big screen debut with the Park Hee-Joon directed 2016 film ‘Come Back to Busan Port’, the filming of which commenced in Busan in June of that year. His role was that of Tae-sung, younger twin brother of Tae-Joo played by Lee Jung-Jin. The story shows how the twin brothers who got separated early in life meet again with the older becoming a detective and the younger a #2 guy of a criminal gang.
He then bagged the leading role of Cha Jin-wook in the South Korean television series ‘My Secret Romance’. It aired on OCN for 13 episodes starting from April 17, 2017, to May 30, 2017, marking the first romantic drama by the cable network.
He is seen as Kang Shin-hyuk, a producer of an entertainment company, in the South Korean TV drama series ‘The Idolmaster KR’ based on ‘The Idolmaster’ video game series by ‘Bandai Namco Entertainment’. The series scheduled to air for 24 episodes aired on April 28, 2017 on Amazon Prime Video and on same date premiered on different SBS-owned pay TV channels namely SBS MTV, SBS funE and SBS Plus.
Hoon has over the years appeared on several reality and variety shows. These included Let's Go! Dream Team Season 2 (2012), Our Neighborhood Arts and Physical Education (2015), Running Man (2016), Law of the Jungle (2017) and I Live Alone (2017) among others.
In June 2017 he and his ‘My Secret Romance’ co-star Song Ji-eun attended a fan meeting in Seoul after the series concluded. It was also reported that month that he would endeavour in a Global Fan Meeting Tour and in that pursuit shall travel thirteen countries to hold such fan meetings.
Although the exact dates are not declared yet sources mention that he will start Global Fan Meeting Tour with Thailand and end the tour in Seoul, South Korea while giving stops in Hong Kong, Indonesia, Taiwan, Vietnam, Malaysia, Philippines, Japan, Singapore, UAE (Dubai), US and Canada.