Genus: Ruyangosaurus LU, XU, JIA, ZHANG, ZHANG, YANG YOU & JI, 2009
Etymology: In reference to the Ruyang County, Henan Province, China, which the holotype locality belongs to, and Greek, sauros, "lizard."

Species: giganteus LU, XU, JIA, ZHANG, ZHANG, YANG YOU & JI, 2009
Etymology: Greek, giganteus, "very large, huge"; indicates that Ruyangosaurus is a huge sauropod dinosaur.

Holotype: 41HIII-002 (Henan Geological Museum)

Locality: Shengshuigou of Shaping Village, Liudian Town, Ruyang County, Henan Province, China.

Horizon: Haoling Formation (Manchuan Formation).

Biostratigraphy:

Age: Early Late Cretaceous.

Material: 1 nearly complete posterior cervical vertebra, 1 nearly complete posterior dorsal vertebra, 1 postrior cervical rib, 1 anterior dorsal rib, proximal portion of right femur, complete right tibia.