禽龙属（学名：Iguanodon，意为“鬣蜥的牙齿”），属于蜥形纲鸟臀目鸟脚下目的禽龙类，是大型草食性动物，身长约10公尺，高3到4公尺，前手拇指有一尖爪，可能用来抵抗掠食动物，或是协助进食。

禽龙的化石多数发现于欧洲的比利时、英国、德国。牠们主要生存于白垩纪早期的巴列姆阶到早阿普第阶，约1亿2600万年前到1亿2500万年前。禽龙的演化位置大约位于行动敏捷的棱齿龙类首次出现，演化至鸟脚下目中最繁盛的鸭嘴龙类，这段演化过程的中间位置。禽龙与年代更晚的鸭嘴龙类，共同属于禽龙类演化支。

禽龙的化石在1822年首次发现，并在1825年由英国地理学家吉迪恩·曼特尔进行描述与命名。在过去的研究历史中，有许多化石被归类于禽龙，年代横跨侏㑩纪启莫里阶到白垩纪森诺曼阶，范围广达欧洲、北美洲、亚洲内蒙古、以及北非。但根据近年研究，这些化石多被归类于其他属，或是创建为新属。目前的唯一有效种是贝尼萨尔禽龙（I. bernissartensis）。

Iguanodon (/ᵻˈɡwɑːnədɒn/ i-GWAH-nə-don; meaning "iguana-tooth") is a genus of ornithopod dinosaur that existed roughly halfway between the first of the swift bipedal hypsilophodontids of the mid-Jurassic and the duck-billed dinosaurs of the late Cretaceous. While many species have been classified in the genus Iguanodon, dating from the late Jurassic Period to the late Cretaceous Period of Asia, Europe, and North America, research in the first decade of the 21st century suggests that there is only one well-substantiated species: I. bernissartensis, which lived from the late Barremian to the earliest Aptian ages (Early Cretaceous) in Belgium and possibly elsewhere in Europe, between about 126 and 125 million years ago. Iguanodon were large, bulky herbivores. Distinctive features include large thumb spikes, which were possibly used for defense against predators, combined with long prehensile fifth fingers able to forage for food.