- Known as the sweetest member.
- He was born to a well-off family; his father is a businessman.
- His older brother is studying Atomic Engineering in Seoul National University.
- His favorite nickname is "Chow-Chow".
- He was scouted by SM, YG, JYP, Cube, Pledis, Woolim and Yuehua entertainments.
- He was scouted by YG twice. He accepted the second offer after the rumors that YG is debuting a new boy group.
- Due to TREASURE's self-isolation, Jaehyuk's birthday VLive for his 20th birthday was cancelled.