美杜莎（希腊语：Μέδουσα、拉丁语：Medusa，又翻译为梅杜莎、墨杜萨），是希腊神话中的一个女妖，戈尔贡三女妖之一，一般形象为有双翼的蛇发女人。她的父亲是福耳库斯，母亲则为海妖刻托。她的头发都是蛇。根据诗人阿波罗多洛斯的《书库》所述，她是戈耳戈女妖之一，外观描述是缠着龙鳞的头，像野猪一般的獠牙，青铜的手爪，金色的翅膀。任何直望美杜莎双眼的人都会变成石像，蛇发女妖美杜莎后来被英雄珀耳修斯斩除。

赫西俄德的《神谱》也称黑发的波塞冬被金发的美杜莎吸引住而与美杜莎共度一夜。欧里庇得斯的《伊翁》中也称美杜莎是盖亚生出来与诸神作怪的妖怪。美杜莎一词有“极度丑陋的女子”之含意。后期的神话中说美杜莎原本是波塞冬所爱的一个美丽少女，由于她竟敢和雅典娜比美，自吹她的美发比雅典娜的还要漂亮，因此激怒了雅典娜，雅典娜把她变成了一个可怕的怪物，还把她美丽的头发变成了一条条盘旋头顶的毒蛇。还有一种说法是波塞冬在雅典娜神殿中非礼了美杜莎，所以恼怒的雅典娜因此惩罚了她。

In Greek mythology Medusa (/məˈdjuːzə, məˈdʒuː-, -sə/, US /məˈduː-/; Μέδουσα "guardian, protectress") was a monster, a Gorgon, generally described as a winged human female with a hideous face and living venomous snakes in place of hair. Gazers on her face would turn to stone. Most sources describe her as the daughter of Phorcys and Ceto, though the author Hyginus (Fabulae Preface) makes Medusa the daughter of Gorgon and Ceto. According to Hesiod and Aeschylus, she lived and died on an island named Sarpedon, somewhere near Cisthene. The 2nd-century BCE novelist Dionysios Skytobrachion puts her somewhere in Libya, where Herodotus had said the Berbers originated her myth, as part of their religion.