迷惑龙属（学名：Apatosaurus）是蜥脚下目梁龙科下的一个属，生活于侏罗纪的启莫里阶到提通阶之间，约1亿5000万年前。牠们是陆地上存在的最大型动物之一，身长约26公尺，体重介于24到32公吨。牠们的属名在希腊文意为「骗人的蜥蜴」，因为他的尾椎早期一直被误认为属于沧龙类。

迷惑龙有着长颈、及鞭状尾巴。与身体相比，头部相当小。牙齿成匙状，是草食性恐龙。前肢略短于后肢。牠们的颈椎比梁龙较短、较重，而腿部骨头较梁龙的结实、较长，被认为是比梁龙更粗壮的恐龙。在正常的移动时，尾巴会离开地面。迷惑龙的前肢有一个大指爪，而后肢的前三个脚趾拥有趾爪。

Apatosaurus (/əˌpætəˈsɔːrəs/; meaning "deceptive lizard") is a genus of extinct sauropod dinosaurs that lived in North America during the Late Jurassic period. Othniel Charles Marsh described and named the first-known species, A. ajax in 1877, and a second species, A. louisae, was discovered and named by William H. Holland in 1916. They lived about 152 to 151 million years ago (mya), during the early Tithonian age, and are now known from fossils in the Morrison Formation of modern-day Colorado, Oklahoma, and Utah, in the United States. Apatosaurus had an average length of 22.8 m (75 ft), and an average mass of at least 16.4 metric tons (18.1 short tons). A few specimens indicate a maximum length of 11–30% greater than average and a mass of 32.7–72.6 t (32.2–71.5 long tons; 36.0–80.0 short tons).