David Gilly (7 January 1748 – 5 May 1808) was a German architect and architecture-tutor in Prussia, known as the father of the architect Friedrich Gilly.
Born in Schwedt, Gilly was the son of a French-born Huguenot immigrant named Jacques Gilly and his wife Marie Villemain. His brother was the physician Charles Gilly. Already at the age of fifteen, Gilly was working in the gardens on the Noteć. Becoming a specialist in building water-features, he was appointed master builder in 1770 (at 22 years of age), and was active between the years 1772 and 1782 in Stargard, Farther Pomerania. Gilly was the first examinee of the newly established Ober-Examinationskommission.
Around 1777, Gilly married Friederike, a daughter of the regimental stable-master Friedrich Ziegenspeck. With her he had two children, Friedrich and Minna (who later married the politician Friedrich Gentz).
In Stargard, Gilly was in 1779 promoted to building director of Pomerania, before being transferred in 1782 to Stettin. As a building director, he designed (among other things) responsibly for the harbour company of Swinemünde and Kolberg. Because Gilly had already made himself widely known among the new generation of newly-qualified architects, he established the "Cameralbau" in Stettin. For King Frederick the Great, he acted as a source of expertise for comprehensive land improvement schemes.
In 1788 Gilly was recalled to Berlin, into the Oberbaudepartement. There he was promoted that very year to be architectural advisor for the provinces of Pomerania, East Prussia and West Prussia, responsible for Kurmark and Altmark. His appointment as vice director of the construction and inspection department lasted four years. As such, Gilly was from 1792 to 1801 in charge of the building of the Bromberger Canal and the reconstruction and extension of the harbour concern of Danzig and Elbing.