Wong is a Southern California native and son of Po-Ping Wong of Kowloon, a dentist and 1965 graduate of UCSF School of Dentistry. His parents emigrated from China in the early 1950s. His paternal grandfather was a General Officer in the Chinese Nationalist Army and his maternal grandfather was a senior railroad executive who aided US Allied forces during World War II and was awarded with the Commander's Award for Civilian Service for his efforts.
