An umbilical cable or umbilical is a cable which supplies required consumables to an apparatus. It is named by analogy with an umbilical cord. An umbilical can supply power to a remote electrical device, or air and power to a pressure suit, for example.

Early space suits used umbilicals, but modern designs carry their own temperature/humidity control, air supply and electric batteries.

Subsea umbilicals are deployed on the seabed (ocean floor) to supply necessary control and chemicals to subsea oil and gas wells, subsea manifolds and any subsea system requiring a remote control, such as a remotely operated vehicle.

A Diver umbilical cable is a cable which supplies breathing gas and other services from a surface supply to a diver.

For shallow water surface supply air diving, the diver umbilical is typically a 3-part umbilical comprising a gas hose, "pneumo" hose, and diver comms/lifeline cable. The "pneumo" hose is open at the diver's end all the way to a pressure gauge on the surface dive control panel, where the supervisor can see the diver's depth in the water at all times.