Marmarospondylus ("marble [reference to the Forest Marble Formation] vertebra") is a dubious genus of sauropod dinosaur from Middle Jurassic deposits in the English Midlands. The type species, Marmarospondylus robustus, was described by Richard Owen as a species of the Late Jurassic genus Bothriospondylus in 1875. The holotype, NHMUK R.22428, a dorsal vertebra, was found in the Bathonian-age Forest Marble Formation at Bradford-on-Avon, Wiltshire. Owen himself in an addendum to the same publication coined Marmarospondylus for B. robustus, presumably due to its being older than B. suffossus. Recent publications have treated Marmarospondylus as a dubious member of Macronaria.