• Birthplace: Seoul, South Korea
• Age: 24
• Height: 182 cm
• Weight: 62 kg
• Website: N/A

Yeonjun (연준) was the first member of TOMORROW X TOGETHER (투모로우바이투게더) to be unveiled. His introduction was via the teaser video, 'Introduction Film - What Do You Do?', uploaded to YouTube on January 10, 2019. His teaser photos were subsequently released over various media platforms.

Pre-debut

Yeonjun auditioned for Big Hit Entertainment (Big Hit) with BTS's song Boy in Luv. Successful, he became a trainee under Big Hit in 2014. His trainee period of 5 years (2014-2019) is the longest amongst all Big Hit artists. This includes his fellow TXT members.

Before joining Big Hit, Yeonjun was a trainee of Cube Entertainment.

Yeonjun appears in MMA 2014 as backup dancer.

2019-Present

On January 10, 2019, Yeonjun became the first member of TXT to be revealed.