Hayoung shared her first audition before debuting as an Apink member.

Hayoung continued talking, and said, "Because of that, I told my parents that I wanted to be a singer, and they encouraged me to have an audition and get accepted. My first audition was at SM Entertainment, where Girls' Generation is. Then after numerous interviews, one of the team leaders moved to Cube Entertainment and took me along with him, and I made a debut with Apink."

Oh Hayoung became a trainee at Cube Entertainment for one and a half years. She debuted as an Apink member as the vocalist, rapper, and maknae of the group on April 19, 2011. Though, many people don't believe that she is the youngest among the members as she has a mature physical appearance.

Apink is generally known for its charming, innocent, and girlish image, plus its outstanding dancing skills and unforgettable live stages. In addition, fans claim that the members are very adorable and likable. And what sets Apink apart from other girl groups is that they stick with either cute, upbeat, pop songs or sweet ballads, which perfectly fits the members.

Besides group activities, Oh Hayoung has participated in many variety shows and acting projects. In 2014, she appeared as MC in the program "Weekly Idol" together with Apink co-member Bomi for several episodes. In 2016, she joined the female edition of the show "Law of the Jungle." In November, she played a role in the two-episode web drama titled "Please Find Her." In 2018, she was cast in "Love, Stay in Memory," a six-episode sci-fi romance web drama.

Apart from contributing her vocal skills, Hayoung also helped in lyrics writing. She is the lyricist of Apink's 2015 track "What a Boy Wants," and the co-writer alongside Eunji for their 2016 duet single titled "It's You."

On another news, Oh Hayoung recently made her solo debut releasing her first mini-album called "OH!" with the title track "Don't Make Me Laugh."