Jules Gabriel Henri de Sibour (December 23, 1872 – November 4, 1938) was a French architect who worked in Washington, DC.

He was born in Paris, France, to Vicomte Gabriel de Sibour and Mary Louisa Johnson of Belfast, Maine.

[citation needed] He attended St. Paul's School in New Hampshire, then earned a degree from Yale University in 1896, where he was a member of Skull and Bones.

He collaborated with the Boston firm of Desmond and Lord on the Clapp Memorial Building (443 Congress Street, Portland, Maine) opened in 1920.

[citation needed] Working in the Beaux-Arts style throughout his career, de Sibour's buildings are characterized by their extensive applied decoration and the French influence in their design.