An insulation-displacement connector (IDC), insulation-displacement technology/termination (IDT) or insulation-piercing connector is an electrical connector designed to be connected to the conductor(s) of an insulated wire or cable by a connection process which forces a selectively sharpened blade or blades through the insulation, bypassing the need to strip the wire of insulation before connecting. When properly made, the connector blade cold-welds to the wire, making a highly reliable gas-tight connection.

Modern IDC technology developed after and was influenced by research on wire-wrap and crimp connector technology originally pioneered by Western Electric, Bell Telephone Labs, and others. Although originally designed to connect only solid (single-stranded) conductors, IDC technology was eventually extended to multiple-stranded wire as well.

Such connections are usually seen in low-current applications such as telecoms, networking and signal connections between parts of an electronic or computer system.

Ribbon cableRibbon cable (also called multi-wire planar cable and suitcase connector) is designed to be used with multi-contact IDC connectors in such a way that many IDC connections can be made at once, saving time in applications where many connections are needed. These connectors are not designed to be reusable, but can often be re-used if care is taken when removing the cable.

Pin 1 is typically indicated on the body of the connector by a red or raised "V" mark. The corresponding wire in a ribbon cable is usually indicated by red coloration, a raised molded ridge, or markings printed onto the cable insulation.

Telephone and network plugsIn some types of telephone and network plug, including the BS 6312 and the registered jack (RJ) family, generally separate wires in a sheath are used. In these applications, the outer sheath is stripped then the wires are inserted into the connector and a special crimp tool is used to force the contacts into the wires. Traditionally these connectors have been used with flat cable which makes it easy to ensure the right wires go into the right slots. However modular connectors used with Category 5 twisted pair cable require careful arranging of the wires by hand before inserting them into the connector.