Go Joon made his acting debut in the 2001 film Wanee and Junah. In 2008, he landed a role in the box-office hit Scandal Makers. In 2010, he was cast in two SBS dramas, namely Dr. Champ and Daemul. In 2018, he became part of the main cast of the JTBC series Misty, which was nominated for Best Drama at the 54th Baeksang Arts Awards. In 2019, he won Best Supporting Actor at the 27th SBS Drama Awards as well as Star of the Year at the 12th Korea Drama Awards for his performance in the SBS series The Fiery Priest. In 2020, he acted alongside Jang Nara in the tvN romantic comedy Oh My Baby. Later that year, he headlined the KBS2 series Cheat on Me, If You Can, in which he was nominated for an Excellence Award at the 34th KBS Drama Awards.

In a magazine interview, Go Joon revealed that he was a socially difficult child in the past. He said that attending the church helped him get used to be around people. He shared that he became an altar boy and also once wanted to become a priest.