William Manor Jardine was born in Oneida County, Idaho, on January 16, 1879. He attended Utah State College of Agriculture (Utah State University), receiving his BA in 1904. He attended graduate school at the University of Illinois (1906).

In 1906, he accepted appointment as assistant professor of agronomy at Utah State (1906), and he later taught at Kansas State University (1910). He served as assistant U.S. cerealist (1907-1910). While at Kansas State, Jardine became director of the Agriculture and Agronomy school and Experiment Station (1910) and later dean of the School of Agriculture (1913).

In 1925, President Coolidge appointed Jardine as Secretary of Agriculture, a position he held until 1929. In 1930, Jardine was appointed as U.S. minister to Egypt. Jardine returned to serve as president of the University of Wichita (1934-1949). Jardine died on January 17, 1955.