Karl Gildemeister (11 October 1820 Bremen - 8 February 1869 Bremen) was a German architect.
Gildemeister's studies at the Berliner Bauakademie were followed by study trips to Italy and Greece. In 1852, he contributed to the design of the New York Crystal Palace which was part of the Exhibition of the Industry of All Nations in New York City. Until his early death, he taught at the commercial art school in Bremen. He is known for his detailed historical study of the Bremen Town Hall and Marketplace.
He was the son of Senator Johann Carl Friedrich Gildemeister; the brother of Mayor Otto Gildemeister, also a translator and journalist; and son-in-law of the architect Jakob Ephraim Polzin.