Naashoibitosaurus (from Navajo naʼashǫ́ʼii bitooh—"creek lizard") is a genus of hadrosaurid dinosaur that lived about 73 million years ago, in the Late Cretaceous, and was found in the Kirtland Formation of the San Juan Basin in New Mexico, United States.

[3] When the disconnect became apparent, Hunt and Lucas gave the specimen its own generic name, because the skull did not agree with an edmontosaur, and they considered Kritosaurus indeterminate and thus not usable.

[6] A 2014 study agreed with previous authors that Naashoibitosaurus is similar to Kritosaurus, but found it to be a distinct species.

Its skull, the most thoroughly described portion, has a low nasal crest that peaks in front of the eyes, but does not strongly arch as in Gryposaurus.

As a hadrosaurid, Naashoibitosaurus would have been a large bipedal/quadrupedal herbivore, eating plants with a sophisticated skull that permitted a grinding motion analogous to chewing.