棱齿龙科（Hypsilophodontidae）或称棱齿龙类（Hypsilophodont），名称来源是鬣蜥中的Hypsilophus属，意为“高冠状的牙齿”。棱齿龙类是群小型鸟脚类恐龙，身长平均1到2公尺，被认为是行动快速的草食性二足恐龙。棱齿龙类发现于亚洲、澳洲、欧洲、北美洲、以及南美洲的中侏㑩纪到晚白垩纪岩层间。棱齿龙类传统上包括了所有非禽龙类的二足鸟脚下目恐龙，某些早期种系发生学研究认为棱齿龙类是自然演化支，但最近的研究发现棱齿龙类是并系群，并有一支系往禽龙类演化。某些研究更认为部分棱齿龙类并不属鸟脚下目，目前唯一确定的物种是棱齿龙（Hypsilophodon）。棱齿龙科演化树因为缺乏研究而显得复杂。

Hypsilophodonts (named after Hypsilophodon, itself derived from the Hypsilophus ("high-crested") genus of iguana lizard and literally meaning "Hypsilophus-tooth") were small ornithopod dinosaurs, regarded as fast, herbivorous bipeds on the order of 1–2 meters long (3.3-6.6 feet). They are known from Asia, Australia, Europe, New Zealand, North America, and South America, from rocks of Middle Jurassic to late Cretaceous age. The group traditionally has included almost all bipedal bird-hipped dinosaurs other than iguanodonts, and some early phylogenetic analyses found it to be a natural group, but more recent studies have found that the group is mostly paraphyletic and the taxa within represent a series leading up to Iguanodontia. Some of these studies have moved some traditional hypsilophodonts out of the Ornithopoda, such as Agilisaurus and Othnielosaurus (=Othnielia). Thus, the only certain member at this time is Hypsilophodon.