William Christmas Knighton was an American architect best known for his work in Oregon. Knighton designed the Governor Hotel in Portland, Johnson Hall at the University of Oregon, and the Oregon Supreme Court Building and Deepwood Estate in Salem. He served as Oregon's first State Architect from 1911–1915, appointed by Governor Oswald West. By 1915, Knighton had designed ninety building projects as State Architect. In 1919, Knighton was appointed by Governor Ben Olcott as the first President of the Oregon State Board of Architectural Examiners, a position he held until 1922. In 1920, Knighton was elected the sixth President of the Oregon Chapter of the American Institute of Architects. He remained on the Chapter's Board of the Trustees for several years and was Chair of the Chapter Legislative Committee into the 1930s.
In 1924 he formed a partnership with Leslie Dillon Howell, during which he designed buildings including Grant High School.