2016–2018: Produce 101 and Produce 48
In 2016, she participated in the first season of Mnet's new survival show, Produce 101, as a independent trainee but was eliminated in the episode 8 after achieving 40th place. After the show, she signed with Yue Hua Entertainment, where she continued to train. In 2018, she participated in the third season of the Produce franchise, Produce 48, but again was eliminated, now in the episode 11, after achieving 27th place.
2019: Debut in EVERGLOW
On February 18, an article was published on Naver revealing that she and her fellow trainee from Produce 48, Wang Yiren, were confirmed to be members of the upcoming girl group EVERGLOW. On the same day, a teaser video for the girl group was posted on Stone Music Entertainment's channel on YouTube, confirming Sihyeon as their first member. The group debuted in March 18, 2019 with the single album "Arrival of EVERGLOW".
- Her hobbies are cooking, collecting pretty things and nail art.
- She was a trainee for 2 years and 10 months.
- She was the first member to be revealed.
- She's known for her strong resemblance to Suzy.
- Her specialties are singing and dancing.
- Her unique points are her bunny teeth, her healthy hair, her hard work and her long neck.
- She likes Frozen.
- She loves pets.
- Her favourite colour is purple.
- Her role models are Sunmi and U-Know.
- She hates red vegetables.
- Her hobbies are cooking and collecting. She also loves nail-art.
- She is good friends with all the IZ*ONE members, especially with Yena (company mate) and Eunbi.
- Sihyeon and E:U are roommates.