For the mapping grid, see British national grid reference system

The National Grid is the high voltage electric power transmission network in Great Britain, interconnecting power stations and major sub-stations and ensuring that electricity generated anywhere in Great Britain can be used to satisfy demand elsewhere.

In England and Wales the grid was developed by the CEGB and since privatisation has been owned and operated by the National Grid Company. In Scotland the grid is owned and operated by Scottish Power. Although seperately owned and operated, the two grids are interconnected.

There are also under-sea interconnections to Northern Ireland, the Moyle Interconnector , and northern France.