Park Ji-hoo made her acting debut in 2016 through the short film House Without Me. She then played minor characters in a couple of movies before landing her breakout role in the drama film House of Hummingbird in 2018. The film received numerous accolades including the Grand Prix of the Generation 14plus International Jury for the Best Film at the 69th Berlin International Film Festival and the Best International Narrative Feature at the 2019 Tribeca Film Festival. Park Ji-hoo also bagged several Best Actress and Best New Actress wins and nominations for her performance in the movie. In 2022, she played one of the main characters in the Netflix zombie series All of Us Are Dead.

In 2021, Park Ji-hoo’s agency announced that the actress got accepted into Hanyang University’s theater and film department.