Hong was born in Minneapolis, Minnesota, to Frank W. Hong and Lee Shui Fa. His father (Chinese name: Ng Fok Hong) emigrated from Hong Kong to Chicago, Illinois, via Canada, where he owned a restaurant. Hong's grandfather was from Taishan. For his early education, Hong moved to Hong Kong, where he lived in Kowloon, before returning to the United States at the age of ten. He graduated from Minneapolis Central High School. He studied civil engineering at the University of Southern California, where he concentrated the majority of his free time on moving plates and fixing templates for the drill squad. Hong later became interested in acting and trained with Jeff Corey. Hong was a road engineer in Los Angeles County for seven and a half years, acting during his vacations and sick days. He eventually quit engineering for good to devote himself to acting and voice work full-time.