Louis Singleton Curtiss (July 1, 1865 – June 24, 1924) was a Canadian-born American architect. Notable as a pioneer of the curtain wall design, he was once described as "the Frank Lloyd Wright of Kansas City". In his career, he designed more than 200 buildings, though not all were realized. There are approximately 30 examples of his work still extant in Kansas City, Missouri where Curtiss spent his career, including his best known design, the Boley Clothing Company Building. Other notable works can be found throughout the American midwest.