Jo Jinho 조진호 was born on Friday, April 17, 1992. He is the oldest member of Pentagon, older than Pentagon's maknae Wooseok by 5 years and 9 months. He was born in the Chinese Year of the Monkey. Two other group members have January birthdays near his, so Jinho, Hongseok, and Yeo One are all the zodiac star sign Aries. At a height of 168 cm or 5'6", Jinho is the shortest member of Pentagon. He's shorter than the tallest member Wooseok by 20 cm or 7 7/8". Jinho and Yeo One are both from Daejeon.
Pentagon is a very multilingual group; all ten members can speak a second language in addition to Korean. The four members of the group who can speak English are Jinho, Hui, Hongseok, and Kino. Jinho is also one of the five members in the group who can speak Mandarin, along with Hui, Hongseok, Yeo One, and Yanan.
Jinho is the main vocal for Pentagon and his specialty is super high notes. He also likes composing, playing the piano and guitar, and listening to rap music and music from other countries. He enjoys going to movies and musicals and playing games.
Jinho is a former SM Entertainment trainee. In 2010, he made his first debut under the stage name Jino as a member of SM Entertainment’s project boy unit, SM the Ballad. The group consisted of Jay Kim of the Trax, Super Junior's Kyuhyun, Shinee's Jonghyun, and Jinho, usually listed as SM trainee Jino.
The unit released a mini-album titled SM the Ballad vol. 1. Jinho recorded and performed two songs with the unit members, "너무 그리워 (Miss You)" and "Hot Times (시험하지 말기)."
He later left SM to become a trainee at Cube Entertainment. Part of his trainee period at Cube was shown on Mnet's competition reality show, "Pentagon Maker." On the eighth week he completed his Pentagon Graph and was accepted as a member of Pentagon.