电源延长线（也称为延长线）是一个电缆与多个导体用于需要灵活性暂时的电力连接。电源延长线广泛应用于操作中使用的在各类型电机工具、设备、家用电器和机械。

延长线可在商业，工业和住宅应用中使用。有一些延长线可以防水。

A portable cord (also known as portable cordage, flexible cord, or extension cord) is a cable with multiple conductors used for temporary electrical power connections requiring flexibility. The cord can be employed in a range of applications, such as operating motors in small and large tools, equipment, power extensions, home appliances, and machinery.