- She was born in Suwon, South Korea.
- Jeongyeon's birth name is Yoo Kyung Wan. She changed her name in 3rd grade because she was teased because her name sounded like a boy's name.
- She has 2 older sisters: Gong Seungyeon (actress, who appeared in We Got Married) and Seo Yeon (office worker).
- When Jeongyeon was young, she failed the JYP audition. She became a trainee after passing the JYP Entertainment's 6th Open Audition on March 1, 2010.
- Jeongyeon was accepted into JYP and SM in the same day, but chose JYP.
- The leader of Twice was decided by anonymous voting. Jeongyeon was in 2nd place.
- Her representative color is Yellow-Green.
- She likes Nanoblocks and Legos.
- Jeongyeon knows how to play the saxophone (Star King Ep. 441) and she also learned how to play the guitar. (Weekly Idol)
- Jeongyeon likes ddeokbokki, meat, and golbangee muchim.
- She doesn't like lotus.
- The happiest part of Jeongyeon's day is taking off her contact lenses.
- Jeogyeon is called the mother of TWICE. (Amigo TV)
- Jeongyeon is ambidextrous. (Twice Showtime)
- Jeongyeon is in charge of cleaning the dorm. She likes cleaning.
- She appeared in GOT7's "Girls Girls Girls" MV and miss A's "Only You" MV.
- Jungyeon said that if she were a male, she would date Nayeon, because she's cute (Busan fansign).
- At Incheon fansign she said she would date Mina.
- She doesn't use perfume, she uses body mist instead.
- In Twice's dorm Jungyeon is the one who catches the bugs. (Jihyo is the one who's the most scared of them)
- She has 2 dogs: a white Pomeranian named Bbosongie and a Poodle named Nanan.
- She has the most confidence in her legs and teeth.
- She initially wanted a modeling career.
- Jeongyeon's father Yoo Chang-joon was a private chef for former president Kim Dae-jung, as well as a head chef of the Seoul Plaza Hotel for over 20 years, specializing in Korean cuisine.
- Her mother works at a Japanese restaurant owned by her maternal aunt.
- Jeongyeon stated that she will start to grow out her hair in 2017.
- She likes buying "convenient" products ("We Like Zines")
- Jeongyeon is ranked 66th on TC Candler "The 100 Most Beautiful Faces of 2018".
- In the dorm, Jeongyeon and Momo share a room.
- Jeongyeon's ideal type: "Someone who makes me feel comfortable; Someone funny who can amuse me."