The pink triangle (German: Rosa Winkel) was one of the Nazi concentration camp badges, used by the Nazis to identify male prisoners in concentration camps who were sent there because of their homosexuality. Every prisoner had to wear a triangle on his or her jacket, the color of which was to categorize him or her according "to his kind." Jews had to wear the yellow badge, and "anti-social individuals" (which included vagrants, "work shy" individuals and often, but not exclusively, lesbians [citation needed]), the black triangle. The black triangle as a symbol of lesbian or feminist solidarity, a counterpart to the gay pink triangle, probably originated from the Nazi "asocial" black triangle.

The inverted pink triangle has become an international symbol of gay pride and the gay rights movement, and is second in popularity only to the rainbow flag.