A windsock is a conical textile tube that resembles a giant sock. Windsocks can be used as a basic guide to wind direction and speed, or as decoration.

Windsocks are used to tell wind speed and the direction of the wind speed itself. Windsocks typically are used at airports to indicate the direction and strength of the wind to pilots and at chemical plants where there is risk of gaseous leakage. They are sometimes located alongside highways at windy locations.

At many airports, windsocks are lit at night, either by floodlights on top surrounding it or with one mounted on the pole shining inside it