Park Sung-hoon began his entertainment career in the mid-2000s. In 2015, he became part of the SBS series Six Flying Dragons, which won him Best New Actor at the 23rd Korea Culture and Entertainment Awards. In 2018, he bagged the Best New Actor trophy at the 32nd KBS Drama Awards for his work in Black Knight and My Only Ally. His performance in the latter also earned him a Best New Actor for TV nomination at the 55th Baeksang Arts Awards. In 2020, he headlined the KBS2 drama Memorials, which earned him an Excellence Award as well as the Best Couple Award with Nana at the KBS Drama Awards.

Park Sung-hoon is in a relationship with actress Ryu Hyun-kyung.