Clothes line is any type of string, rope, cord, or twine that has been stretched between two points, generally outside, a few feet above the ground. Clothing that has recently been washed is hung along the line to dry, using clothespins.

Clothes lines became somewhat less popular with the invention of the Clothes dryer, especially in North America, since it reduces not only labour but a dependency on fair weather.

Clothes dryers use significant amounts of electricity, so environmental organizations advocate the use of clothes lines, since it reduces energy consumption and the consequent pollution, depletion of fossil fuel and CO2 emission (see Global Warming) associated with electricity generation. However, since clothes lines may be perceived as associated with poverty, zoning and other regulations may prohibit their use. This is particularly true in California. In Scotland the outlook is different: most tenement buildings are attached to a drying green , a communal area which, while it may double as recreational space, is predominantly a place with many clothes lines.

This device lent its name to a move in professional wrestling, in which one wrestler runs towards another and extends their arm out from the side of the body and parallel to the ground, knocking over the other as they run by.