Casper was born in Ridgewood, New Jersey, the son of Diane, a retired nursery school teacher, and Casper Robert Van Dien, Sr., a retired U.S. Navy commander and fighter pilot. The name Casper is a family tradition, given to the eldest son of his family for more than 11 generations. There is a long military tradition in Van Dien's family. Aside from his father, his grandfather was a Marine during World War II. Van Dien is a descendant of an old Dutch family long settled in the New York area; his other heritage includes Swedish, French, English and Native American.

Van Dien grew up in Ridgewood, New Jersey. The street on which he grew up in New Jersey, Van Dien Avenue, was named after his great great grandfather. He grew up on the same block as actor Robert Sean Leonard, and raced go-carts in their neighborhood.[citation needed] In high school, he was often referred to as "Ken doll" due to his good looks, and got into many fights for that reason. Coincidentally, he was later des