He is divorced and has a daughter, named Kim Yu-ju (김유주, born 2004) and a son. He currently serves as a catcher of entertainment baseball club, Han (한, 恨). Moreover, he commentates several professional football matches as a maniatic perspective, when the national team plays, including 2006 World Cup and 2008 Beijing Olympics.
During his early years as a Chuncheon High School student, he played baseball as an outfielder of the school's semi-professional team. After graduation, with strong suggestion from Korean pop singer, his friend Yoon Do-hyun (lead singer of YB), and bassist Ko Beum-jun, he started his musical career in 1997, with a creation of a band called 'Hot Potato' (뜨거운 감자).
His popularity has increased, since April 2006, he joined the guest of the Friday-night popular music variety programme, Yoon Do-hyun's Love Letter, hosting a segment called Making a gorgeous world with 'slanting' Kim C (삐딱이 김C와 아름다운 세상 만들기, ~ May 2007) on KBS2. Since then, he appeared in a wide range of Korean television programs from variety show to documentaries. Previously, he quoted about his frequent media appearances that, the reason why he acts in such variety shows is to advertise his music.
Although, as a singer, some of his songs reached 1st in the Korean pop charts. Kim plays the guitar and has a deep, classical singing voice. His memorable songs to the public are "Don't Worry Yohey!" (걱정마 Yohey!), "Lady Away Following Spring Blows" (봄바람 따라간 여인), and most recently with "Rain Tears" (비 눈물).
Since October 2007, he appeared on the KBS2's Happy Sunday: 1 Night 2 Days (1박2일) as one of the regular cast members, himself replacing Ji Sang Ryul. In his first episode, while stuck with no money and food, Kim, together with ballad singer Lee Seung-gi with the host Kang Ho-dong sang and played the guitar, earning about ₩8,866. Kim C is also known for his unique style of playing guitars and writing several lyrics.
Kim C was well loved as a quiet and rational character in '1 Night 2 Days'. While he wasn't a master in variety like the other cast members, he showed himself to be the physical agile and intelligent member of the cast, helping them complete various missions which seemed impossible at times, including Bungee Jumping. Kim is also perceived as the "Master" in being able to eat various foods that the rest of the cast can't eat. Kim C confirmed that he would be leaving the show in May 2010, after nearly 3 years of joining 1 Night 2 Days. This news came after there has been speculations of him leaving the show earlier.
As for the reasons of leaving the show, it has been revealed that Kim C will be going overseas to further his studies in Berlin for at least a year. He later confirmed in 2014 that he had stayed there for 15 months. The last filming of the show was completed in KyeongBok KyeongJoo for the Student Trip Special. During this time, the other 1 Night 2 Days Cast like members Kang HoDong, Lee SooGeun, Lee SeungGi, MC Mong, Eun JiWon and Kim JongMin bade him farewell and presented him with a mosaic as a gift. Kim C had confirmed that he had voiced his intentions to leave the show 6 months prior, but never informed the rest of the cast until 2 days before the filming to not disrupt the usual filming patterns of the show. Kim C’s agency representative voiced, “We talked about him going abroad for his studies before. But we did not know about him leaving 2Days 1Night. We are still discussing the details with KBS.” There were also new reports that there are no plans for the show to add one more member after Kim C leaves. After Kim C's departure, he remained to narrate for the show for a few episodes in 2010 before leaving overseas.
Meanwhile, Kim C released a movie soundtrack ‘See Saw’ as part of band Hot Potato which is well received by music fans. Kim C also has his own Radio Show, named "Kim C's Music Show", which broadcasts on KBS Cool FM every day from 4:00 to 6:00pm. Notable guests have included Jo In Sung, Gong HyoJin and Lee Hyori. Kim C started hosting in 2013 and stayed on the show for only a year.
Kim C also appeared in various variety shows, including We Got Married (Where he made a cameo during the Cho Jung Chi- Jung In Arc) and Infinity Challenge Music Festival 2013 (Where he partnered with Jung Jun Ha to form the duo "Double Play". He composed and later performed the song "Will be Gone" featuring Lee Sora and rapper Beenzino with Jung). In recent times, Kim C has concentrated to electronic music as well as his forte in K-indie music.
As of 2016, Kim C continues to release music through Hot Potato and his Soundcloud page. He is also the new host for a travel variety show on MBN, 여행생활자 집시맨