Gaspard Baillieul (16??-1744) was a French geographer, engraver, publisher, printer, and engineer active during the late 17th and early 18th centuries based in Paris. Other spellings of his surname include Baillard, Bailleul, and Bailleux. He advertised himself as Engineer and Geographer to the King from at least 1735 and operated out of an office located near the Post au Change in Paris.