Electromagnetic shielding is the process of limiting the flow of electromagnetic fields between two locations, by separating them with a barrier made of conductive material. Typically it is applied to enclosures, separating electrical devices from the 'outside world', and to cables, separating wires from the environment the cable runs through. Electromagnetic shielding used to block radiofrequency electromagnetic radiation is also known as RF shielding.

The shielding can reduce the coupling of radio waves, visible light, electromagnetic fields and electrostatic fields, though not static magnetic fields. (A conductive enclosure used to block electrostatic fields is also known as a Faraday cage.) The amount of reduction depends very much upon the material used, its thickness, and the frequency of the fields of interest.