Mark was born in the early fifties to internationally recognized animators John and Faith Hubley, He was raised in New York City along with siblings Ray, Emily, and Georgia, and graduated from Reed College in 1974 with a degree in English literature. Mark now lives in Midway, Kentucky where he has worked in the thoroughbred industry for most of his adult life. He frequently visits his sons in Boulder and Breckenridge Colorado where he has second a home.