Hungarian-born Wilmos Bela Sandorhaji arrived in the U.S. in 1910 with qualifications from the Royal Academy of Art in Budapest and the Ecole de Beaux Arts in Paris. He enjoyed his first success as a portrait painter in New York prior to the outbreak of World War I. By the time he relocated to Hollywood ten years later, he had adopted his wife's maiden name of Darling. After a brief stint with the American Film Company, he signed a contract with (20th Century) Fox in 1922. Until his departure in 1946, Darling held a position as the pre-eminent supervising art director at the studio, involved in equal measure with prestige releases and B-pictures. He provided striking sets for a variety of exotic subjects, from Zoo in Budapest (1933) to The Rains Came (1939), on several occasions working with the illustrious director John Ford. Darling was nominated for seven Academy Awards, winning three times: for Cavalcade (1933), The Song of Bernadette (1943) and for Anna and the King of Siam (1946).

After his retirement from film work in the mid-1950s, Darling devoted himself to painting idyllic desert landscapes and coastal scenes in oil or watercolour on canvas. Until his death in September 1964, Darling was strongly involved in local arts communities in Laguna Beach and Palm Springs, maintaining residencies in both. He was inducted into the Art Director's Guild Hall of Fame in 2011.