In Greek mythology, Narcissus (; Ancient Greek: Νάρκισσος Nárkissos) was a hunter from Thespiae in Boeotia (alternatively Mimas or modern day Karaburun, Izmir) who was known for his beauty. According to Tzetzes, he rejected all romantic advances, eventually falling in love with his own reflection in a pool of water, staring at it for the remainder of his life. After he died, in his place sprouted a flower bearing his name.

The character of Narcissus is the origin of the term narcissism, a fixation with oneself. This quality, in turn, contributes to the definition of narcissistic personality disorder, a psychiatric condition marked by grandiosity, excessive need for attention and admiration, and an inability to empathize.

Like the myth of Laius and Chrysippus, the myth of Narcissus is a Boeotian pederastic cautionary tale, a story meant to teach by counter-example.