Born in Manchester, England on April 1, 1842, William Lees Judson immigrated to the U.S. with his family in 1852. He was educated in the public schools of Brooklyn and Ontario, Canada. He enlisted in the U.S. Army during the Civil War and afterwards spent several years as a farmer in Ontario.
He studied art in New York City with John B. Irving (1872-73) followed by three years in Paris at Académie Julian under Jules Lefebvre and Gustave Boulanger. Returning from Europe, Judson worked in New York City, Toronto and London, Canada until 1890 when he moved to Chicago where he was active as a portraitist.
After the Chicago World's Fair, he moved to southern California where he taught at the Los Angeles Schoo