Tlatolophus (meaning "word crest") is a genus of hadrosaurid dinosaur belonging to the tribe Parasaurolophini.

The holotype, specimen CIC/P/147, was first discovered as a semi-articulated tail in 2005 in sediments of the Cerro del Pueblo Formation in Coahuila, Mexico.

[2] The holotype specimen of Tlatolophus, CIC/P/147, represents a large individual, around 8 metres (26 ft) in length.

The nasal cavity occupies the structure's entirety, including the caudal end of the supracranial crest which is comma-shaped, hence the binomial name.

The cladogram below displays the results of their phylogenetic analysis:[2] Tlatolophus galorum Blasisaurus canudoi Charonosaurus jiayinensis Parasaurolophus cyrtocristatus Parasaurolophus tubicen Parasaurolophus walkeri Kazaklambia convincens Arenysaurus ardevoli Amurosaurus riabinini Sahaliyania elunchunorum Velafrons coahuilensis Hypacrosaurus altispinus Hypacrosaurus stebingeri Olorotitan arharensis Magnapaulia laticaudus Corythosaurus casuarius Corythosaurus intermedius Lambeosaurus lambei Lambeosaurus magnicristatus