Wiard B. "Bill" Ihnen (August 5, 1897 – June 22, 1979) was an American art director.
Born in Jersey City, New Jersey, the son of an architect, he first studied his father's profession at Columbia University. He later attended the École des Beaux-Arts de Paris. Ihnen was married to Edith Head from 1940 until his death from prostate cancer in 1979, aged 81.
Ihnen won two Academy Awards in the category Best Art Direction.