自恋（英语：narcissism），形容自我陶醉的行为或习惯，可被视为是一种性格，或是一种集体行为造成的现象。严格来说，可被观察到自恋现象的人物应区分为三种类型：潜意识产生的自恋、与社会角色伴生的自恋、和自恋型人格障碍，造就这三者的原因差距甚大。

自恋的英文名词来自希腊神话。那耳喀索斯（希腊语：Νάρκισσος，拉丁化：Narcissus）是一名俊美的希腊青年，他拒绝了女神厄科（意译：回声，是一名有漂亮嗓子的女神）的求爱。他注定会爱上他自己在湖中的倒影，作为惩罚。因为没法令他的爱变得完满，他日益消瘦，最后变成了一朵以他命名的花——水仙。

Narcissism is the pursuit of gratification from vanity or egotistic admiration of one's own attributes. The term originated from Greek mythology, where the young Narcissus fell in love with his own image reflected in a pool of water.

Narcissism is a concept in psychoanalytic theory, which was popularly introduced in Sigmund Freud's essay On Narcissism (1914). The American Psychiatric Association has had the classification narcissistic personality disorder in its Diagnostic and Statistical Manual of Mental Disorders (DSM) since 1968, drawing on the historical concept of megalomania.