禽龙科（Iguanodontidae）是鸟脚下目的一科，生存于白垩纪早期到中期，分布于今日的亚洲、欧洲、非洲、以及北美洲等地。最著名的属是禽龙，是最早被命名的恐龙之一。

禽龙科具有过渡的外形，以及许多衍化的特征。牠们的脊椎上有骨化肌腱，前上颌骨缺乏牙齿，颌部具有齿系，固定的胸骨，胸骨的形状为肾脏状到斧状。禽龙科可以用二足或四足方式移动。某些属的拇指具有尖刺，可能作为武器，而中间三指可用于行走，小指可用来操作物体。

Iguanodontidae is a family of iguanodontians belonging to Styracosterna, a derived clade of the iguanodont group Ankylopollexia. In the past, Iguanodontidae became a repository for any ornithopod that did not belong in either Camptosauridae, Hadrosauridae or Hypsilophodontidae. However, a number of studies demonstrated that Iguanodontidae as traditionally defined is paraphyletic with respect to Hadrosauridae. Nevertheless, a handful of recent cladistic analyses have found support for a monophyletic Iguanodontidae consisting of a handful of taxa, including Barilium, Bolong, Iguanodon, Jinzhousaurus, Mantellisaurus, Ouranosaurus, and Proa.