Kang was born in Clarkston, Georgia, to South Korean immigrant parents. He was raised by his Korean mother and African American stepfather in Gainesville, Georgia. He moved to Barstow, California, while in high school.
Kang attended the University of California, Riverside. While in college, he chose acting over law school, a decision that disappointed his parents, who worried that the lack of Asian Americans on American television meant a lack of job prospects.