Park Ha-sun made her acting debut in the 2005 SBS series Love Needs a Miracle. In 2010, she became part of the main cast of the hit MBC sageuk Dong Yi, which won her Best New Actress at the MBC Drama Awards. Her performance in the series also earned her a Best New Actress for TV nomination at the 47th Baeksang Arts Awards. In 2011, she starred in the popular MBC sitcom High Kick 3: Counterattack of the Short Legs. She took home an Excellence Award at the MBC Entertainment Awards as well as the Best Variety Performer trophy at the 48th Baeksang Arts Awards for her work in the sitcom. In 2014, she appeared in the SBS action thriller Three Days, in which she was nominated for a Top Excellence Award at the SBS Drama Awards. In 2018, she was named Best Supporting Actress at the 38th Golden Cinema Film Festival for the action comedy film Midnight Runners. In 2020, she was cast in the eight-episode tvN series Birthcare Center, which scored her a Best Supporting Actress nomination at the 57th Baeksang Arts Awards.

Park Ha-sun and actor Ryu Soo-young tied the knot on January 22, 2017. They were co-stars in the 2013 MBC series Two Weeks. They welcomed their daughter on August 2, 2017.