William T. Dillard was born on 2 September 1914 in Mineral Springs, Howard County, Arkansas. His parents Thomas and Hattie ran a country store. Dillard graduated from the University of Arkansas with a degree in Business Administration and earned a Master's Degree from Columbia University.
Dillard returned to Arkansas and opened his first retail store in 1938 in the town of Nashville, Arkansas. By the turn of the century, Dillard's Department Stores was the third largest department store chain in the United States.
Dillard died at his home in Little Rock.