Fukuisaurus (meaning "Fukui (Fortunate) lizard") is a genus of herbivorous ornithopod dinosaur that lived during the Early Cretaceous in what is now Japan.

[1] Remains of Fukuisaurus were discovered in 1989, in Katsuyama, Fukui Prefecture, in rocks from the Kitadani Formation, dating to the Barremian.

[4] Being a bipedal, optionally quadrupedal, animal, it was similar in general build to Iguanodon, Ouranosaurus and Altirhinus.

According to the describers Fukuisaurus was exceptional in that its skull was not kinetic: the tooth-bearing maxilla would be so strongly fused to the vomer that a sideways chewing motion would have been impossible.

[1] Fukuisaurus was assigned by its describers to Iguanodontia, although the presence of a posterolateral process of the sternum indicated that it likely also belongs to Styracosterna.