Willard Frank Libby was born in Grand Valley, Colorado, on December 17, 1908, the son of farmers Ora Edward Libby and his wife Eva May (née Rivers). He had two brothers, Elmer and Raymond, and two sisters, Eva and Evelyn. Libby began his education in a two-room Colorado schoolhouse. When he was five, Libby's parents moved to Santa Rosa, California. He attended Analy High School, in Sebastopol, from which he graduated in 1926. Libby, who grew to be 6 feet 2 inches (188 cm) tall, played tackle on the high school football team.