Casey King was born to Scott and Kelly (nee' King) Leslie in Pittsburgh Pennsylvania. The second oldest of four boys, Casey grew up playing sports such as hockey, baseball, and football. In high school, his family relocated to Orlando, Florida. He was an exceptional football player and earned a scholarship to play at St. Olaf College in Northfield, Minnesota. He attended college for two years before moving to Los Angeles to pursue a career in acting. He has studied with Robert Carnegie at Playhouse West in North Hollywood and has worked in several plays there. He has appeared in The Asylum's 2-Headed Shark attack with Brooke Hogan and Carmen Electra. He has also appeared in several national commercials for Gatorade, Griffin Technology, and Samsung as well as small independent films.