Actor Park Ho-san has voiced his support for colleague Yang Seung-ho's new YouTube channel. Park said in an October 15 post that Yang had opened a YouTube channel and encouraged people to subscribe. The channel is called Bulkkot Namja Yang Seung-ho. An image accompanying the post shows a person apparently speaking toward a camera indoors, with captions on the screen and instruments and a keyboard behind them. Park also included tags naming MBLAQ, Yang and the channel.

Park said he first met Yang through the musical Gwanghwamun Sonata. Recalling how young Yang was at the time, Park remarked that he had since grown up. Playing on the channel's name, Park said he would give Yang a nickname meaning a man of depth. Park described Yang as warm and friendly without making a show of it. He also said he believed Yang would keep moving forward in whatever he did and invited others to follow the channel.

Park made his debut in the 1997 film Blackjack. He played Kang Cheol-du in Prison Playbook and Park Sang-hoon in My Mister. His subsequent television roles include Jeon Chun-man in Less Than Evil, Kwon Young-goo in Pegasus Market and Im Jae-pil in True Beauty. He played Yoo Dong-pil in The Penthouse II and The Penthouse III and Park Min-geon in Taxi Driver 2. He has also appeared on Life Bar, Knowing Bros and Problem Child in House, and was a regular panelist on Field Marvel.

In 2018, Park won the TV supporting actor award at the 54th Baeksang Arts Awards for Prison Playbook. The same year, he received an acting award at the 6th Asia Pacific Star Awards for My Mister. In 2022, he won a supporting actor award at the 13th Korea Drama Awards for Today's Webtoon and the top actor award in the daily and short drama category at the MBC Drama Awards for Wild Boar Hunting. His film credits include the 2024 releases Dead Man and Project Silence and the 2025 film Omniscient Reader's Viewpoint. He played Ivan in the 2024 play Art. He appeared in the 2025 stage productions Kihyungdo Play and White Rabbit Red Rabbit, and played Michael in the musical Cabin during its 2025–2026 run. Park has served as a promotional ambassador for the Seoul Theater Association since 2022.

Park was scheduled for a special appearance in Meet in Seomyeon, a featured performance at the 2026 Seomyeon Street Arts Festival in the Seomyeon 1st Street area of Busan on October 16–17. The joint performance was described as involving about 150 people, including the Busanjin District municipal joint choir and Dongseo University's musical theater department. His upcoming roles also include Roteshu in the drama The Remarried Empress and Tae-sik in the film Mad Dance Office.