A black telephone cable is a type of cable used for telephone connections. These cables typically consist of one or more twisted pairs of copper wires encased in a black outer insulation or jacket. The black colour of the jacket helps distinguish it from other types of cables used for various purposes, such as Ethernet cables, which often come in different colours like blue, yellow, or grey.

Black telephone cables are used to connect landline telephones to telephone jacks or outlets in homes, offices, or other buildings. They transmit analogue signals that carry voice communication, allowing people to make and receive phone calls. While many modern telecommunications systems have shifted to digital technology and wireless communication, traditional black telephone cables are still in use in some areas, particularly for landline connections and legacy phone systems.