- Nayeon was originally set to debut in the girl group 6mix with Jeongyeon, Jihyo and Sana.
- She's one of the most popular members in Korea.
- When she was a kid, Nayeon entered a child model contest and got cast by JYP. At the time, her mom refused to let her attend the audition, but 10 years later, in 2010, instead of entering a cram school to study harder, Nayeon secretly attended JYP Entertainment's 7th Open Audition and became a trainee.
- She was the first Sixteen member to be announced and also the first member to be confirmed in Twice.
- She is cheerful and always tries to stay positive.
- She is able to remember dances and songs very quickly.
- However: She struggles with remembering lyrics and scripts.
- Nayeon's favorite Pokemon is Squirtle. She also claims the she looks like Squirtle.
- Her zodiac sign is Virgo.
- She has a younger sister named Im Seo-Yoon.
- She has the largest hands and feet relative to her height.
- Her favorite songs are “When I Was Your Man” by Bruno Mars and “Just A Little Bit of Your Heart” by Ariana Grande.
- Her favorite colors are beige, sky blue, and khaki.
- She is called by fans a "fake maknae".
- She is scared of fireworks.
- She is close friends with BLACKPINK’s Jisoo and Jennie since predebut.
- Both Nayeon and Jisoo can understand English well, even though they can't speak fluently.
- Her left leg is weak due to her being in a car accident when she was still in her childhood days.
- She cannot eat sushi that isn’t salmon sushi and also cannot eat chicken feet.
- She like sweet foods.
- One of her hobbies is to collect lipsticks and she has a collection of them. Hence her nickname, "lipstick holic" gained during her SIXTEEN days.
- When Nayeon got her first paycheck, she gave it all to her parents.
- She is a big fan of Girls Generation's Taeyeon, F(x)'s Krystal, and IU.
- Despite her MBTI being tested ISTP, she is not good with tools in hand. She once cut strawberries with the back of a paring knife, leading to wastage and poor presentation.
- She is the only "Thinker" in the group (XXTX).
- She sleeps with her eyes open.
- Her favourite sport is badminton.
- She would like to babysit one day.
- She says whatever is on her mind.
- She currently attends Konkuk University.
- During her special live on her birthday, Red Velvet's Yeri called her.
- Her dog was named Kukkukk by Chaeyoung.
- She wrote the song ''24/7'' along with Jihyo from their full-length album Twicetagram.
- She loves to talk with dolls. Like a lot. Members love to make fun of it.
- During an encore of TWICE’s song “Likey,” Nayeon and Yeri were spotted cutely rocking the choreography on stage together.
- TMI: “I put my hair short. It was originally attached with a long length, but it was always the same, so I put it a little shorter.” [1]
- Her favorite movie is Eternal Sunshine Of The Spotless Mind, having seen it multiple times
- In the Fandom, Nayeon is part of the Snake Trinity with Sana and Mina
- Her phone is an Iphone 11 (Purple) [2]
- Nayeon owns a Nintendo Switch, just like Momo, Jihyo, Jeongyeon and Mina
- She has a dog named Kookeu [3]
- She is really good at Chinese whispers by lip-reading.
- According to Jeongyeon: She suffers from rhinitis. It gets really bad at times.
- She likes oil, so much so that she would eat butter right from the block, or slurp olive oil right from the bottle.
- She also likes anything with kimchi.
- She can fold her tongue into flower shape.
- Even before 2WICE's Date with Tzuyu in 2022, she had never eaten out with only one other member, even when she had spent time with another member alone doing other things.
- She prefers wine over spirits, or cocktails containing them, as she was seen spitting cocktails during award shows before.
- She shared the same name as Kim Nayeon, aka SAdness Manager, who was the group's manager from debut until 2018.
- Her eyesight is -2.5
- She is good friends with Yeri (Red Velvet), Sowon (GFRIEND), and Jeon Somi (Soloist, ex I.O.I).