摩根勒菲（英语：Morgan le Fay，别名：Morgana、Morgane、Morgaine、Fata Morgana）是亚瑟王传奇中登场的邪恶女巫。她的名字来自法语，其形象似乎是在12世纪早期才基本定型的，并以威尔士莫德伦—阿瓦拉的女儿和法国布里多尼民间传说中的水中仙子为蓝本。通常摩根勒菲与凯尔特神话中的战争女神摩莉甘与统治鬼神世界阿瓦隆的死亡女神摩根（Morgen）视作同一人物。

摩根勒菲既是贵妇也是荡妇，既是邪恶的巫后也是美好的仙女，她有两种截然不同的形象，一是美丽的妙龄少女，另一个则是年迈的老妇人，无论她的身份是什幺，她通常都是邪恶的化身且精通医术。传说中是亚瑟王同父异母的妹妹，多次企图杀害亚瑟王与桂妮薇儿王后，试图篡夺王位。

Morgan le Fay /ˈmɔːrɡən lə ˈfeɪ/, alternatively known as Morgan le Faye, Morgen, Morgaine, Morgain, Morgana, Morganna, Morgant, Morgane, Morgne, Morge, Morgue, and other names, is a powerful enchantress in the Arthurian legend. Early works featuring Morgan do not elaborate her character beyond her role as a fay or sorceress. She became both more prominent and morally ambivalent in later texts, in particular in cyclical prose works such as the Lancelot-Grail and the Post-Vulgate Cycle, in which she turns into a dangerous enemy of King Arthur and antagonist of some tales.