Park Sun-ho initially wanted to become an idol, but after failing to debut in a boy group twice, he decided to pursue acting instead. He landed his first acting gig in the 2013 MBC series Gold Rainbow. In 2014, he acted alongside Kim Yoo-jung and Sohn Ji-hyun in the web series Love Cells. He also sang the song After Love for the drama’s official soundtrack. In 2016, he starred in Start Again and I’m Sorry, but I Love You, which aired on MBC and SBS, respectively. His work in both dramas earned him Best New Actor nominations at the 2016 MBC Drama Awards and the 2017 SBS Drama Awards. In 2019, he joined the Mnet reality show Produce X 101 as a contestant.

Park Sun-ho attended Konkuk University. He enlisted for his mandatory military service in August 2020 and was discharged in February 2022.