- Stage Name: Jay (제이)
- Birth Name: Jay Park
- Korean Name: Park Jong Seong (박종성)
- Birthdate: April 20, 2002
- Birthplace: Seattle, Washington, USA
- Blood Type: B
- Height: 180cm
- Education: Hanlim Multi Art School (Practical Dance Dept.)
-  I-LAND
- He was born in the U.S. but moved to Korea when he was 9 years old.
- He is the son of a CEO in Sinar Tours.
- He trained at Big Hit Entertainment for 2 years and 11 months.
- He ranked 2nd in the final episode of I-LAND with 1,182,889 votes.
- He trained at LP Dance Academy before joining Big Hit.