翼龙目（Pterosauria），希腊文意思为“有翼的蜥蜴”，是一个飞行爬行动物的演化支。翼龙类生存于三叠纪晚期到白垩纪末期，约2亿1,000万年前到6,550万年前。翼龙类是第一群能采主动飞行的脊椎动物。牠们的双翼是由皮肤、肌肉、与其他软组织构成的翼膜，翼膜从身体两侧延展到极长的第四手指上 。较早物种的颌部布满长牙齿，具有长尾巴；较晚物种有大幅缩短的尾巴，而某些晚期物种缺乏牙齿。目前已在某些标本的身体、部分双翼发现丝状结构痕迹，显示翼龙类可能已演化出毛发。翼龙类的体型有非常大的差距，从小如鸟类的森林翼龙，到地球上曾出现的最大型飞行动物，例如风神翼龙与哈特兹哥翼龙。

Pterosaurs (/ˈtɛrəˌsɔːr, ˈtɛroʊ-/; meaning "winged lizard") are flying reptiles of the extinct clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period (228 to 66 million years ago). Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger. Early species had long, fully toothed jaws and long tails, while later forms had a highly reduced tail, and some lacked teeth. Many sported furry coats made up of hair-like filaments known as pycnofibers, which covered their bodies and parts of their wings. Pterosaurs spanned a wide range of adult sizes, from the very small Anurognathids to the largest known flying creatures of all time, including Quetzalcoatlus and Hatzegopteryx.