The year she turned 18, she won five golds in the high school division at the National Sports Festival. In 2013, she began competing in the open division for Jeju City Hall. In 2014, she was named to the Incheon Asian Games swimming team and finished fourth in the women’s 4x100 m freestyle relay.
In 2016, she set a Korean record in the 4x100 m freestyle relay (3 min 43.73 sec) at the National Sports Festival. In 2017, she won gold in the women’s open 4x100 m freestyle relay at the National Sports Festival.
The breakthrough yearIn spring 2019, the year she turned 25, her Instagram photos spread in online communities and on social media, and her broad shoulders and arm muscles became a topic. This is when her name became known. That July she set a Korean record in the women’s 4x100 m freestyle relay (3 min 42.58 sec) at the Gwangju World Aquatics Championships, and in August Segye Ilbo wrote that she had risen quickly as a social media star under the nickname Female Ma Dong-seok.
In 2020, she appeared on KBS Joy’s Ask Us Anything and, from August, on E Channel’s Noneun Eonni. That month she signed a management contract with Seal United. In 2021, she appeared on SBS’s Law of the Jungle – Stove League and was an SBS swimming commentator for the Tokyo Olympics while still an active athlete.
In 2022, she threw the first pitch at a KBO League game. In 2023, she appeared in the ssireum contest on JTBC’s Knowing Bros and on MBC’s King of Mask Singer.
In 2024, she appeared in Netflix’s Physical: 100 Season 2 and was a KBS swimming commentator for the Paris Olympics. In 2025, she appeared on Channel A’s Baseball Queen. In August 2026, she attended the press conference for KBS’s Aichi-Nagoya Asian Games coverage as a swimming commentator.
Jung Youin (born May 16, 1994) was named to the Incheon Asian Games swimming national team on Aug 14, 2014, the year she turned 20, and became known in April 2019, the year she turned 25, when her photos spread on social media and in online communities. Noneun Eonni first aired in 2020, the year she turned 26.
Ages are by calendar year (the year minus the birth year), birthdays aside.