[2][4][5][6] Dahyun was recruited to become a trainee for JYP Entertainment after a talent scout saw her performance at a dance festival, and she subsequently trained with them for over three years.

[1] In 2015, Dahyun competed in Sixteen, a reality television show to determine the members of JYP Entertainment's new girl group.

[1][2][6] In October that year, she officially debuted with Twice with the release of their extended play (EP), The Story Begins, and the lead single "Like Ooh-Ahh".

[10][11] In November 2018, Dahyun was criticized by right-wing Japanese lawmaker Masaru Onodera for wearing a T-shirt made by Marymond, an organization that raises funds to help comfort women who were victims of sexual slavery by the Imperial Japanese Army during World War II.

[17] On September 10, Dahyun made her runway debut at New York Fashion Week, wearing the Michael Kors 2025 Spring/Summer collection.