Lillard was born on January 24, 1970 in Lansing, Michigan. His father is of English, French-Canadian, German, Irish, Native American and Welsh descent and His mother is of Danish, English and Portuguese descent. He was raised Christian. He studied at Foothill High School and at American Academy of Dramatic Arts with fellow actor Paul Rudd. Lillard dated Neve Campbell from 1996 to 1998, the two remained friends. And Lillard married Heather Helm since 2000. They have three children.