吉迪恩·曼特尔（Gideon Mantell，全名Gideon Algernon Mantell，1790年2月3日－1852年11月10日），是一位英国产科医生、古生物学家与地质学家。他是第一个发现恐龙牙齿化石的人，并依照牙齿和后来发现的化石，将此归类为禽龙。他开启了对恐龙化石的研究，也做了许多英国南部泥盆纪时期的重要工作。

Gideon Algernon Mantell MRCS FRS (3 February 1790 – 10 November 1852) was an English obstetrician, geologist and palaeontologist. His attempts to reconstruct the structure and life of Iguanodon began the scientific study of dinosaurs: in 1822 he was responsible for the discovery (and the eventual identification) of the first fossil teeth, and later much of the skeleton, of Iguanodon. Mantell's work on the Cretaceous of southern England was also important.