琴蛇属（学名：Trimorphodon）是蛇亚目游蛇科下的一种轻度有毒蛇属，主要分布于美洲、墨西哥等地。目前共有2个品种合共7个亚种已被确认。

琴蛇主要分布于美国、墨西哥、危地马拉、洪都拉斯、尼加拉瓜、哥斯达黎加等地区。

Trimorphodon is a genus of mildly venomous, rear-fanged, colubrid snakes. They are commonly known as lyre snakes, named after the distinctive V shaped pattern on their head that is said to resemble the shape of a lyre. In Mexico, they are commonly called "víbora de uña," or "nail viper." The word Trimorphodon is a combination of three Greek words, 'tri' - three, 'morph' - shape, and 'odon' - teeth, which refers to the three distinct kinds of teeth that lyre snakes have: recurved anterior teeth; shorter middle teeth, and large grooved fangs at the rear of the jaw. There are two distinct species in the genus Trimorphodon, with seven subspecies.