William Lindley joined the Texas National Guard while finishing high school, and received his bachelor of arts in education from Sam Houston State Teachers College in 1939. In 1940 he enlisted as an Aviation Cadet, receiving his wings and commission the following year. After serving in the Army Air Forces in World War II, he transferred to the U.S. Air Force when it became a separate branch of service in 1947. He retired in 1966 as a U.S. Air Force Brigadier General.