List of motorways in the United Kingdom

This list of motorways in the United Kingdom is a complete list of motorways in the United Kingdom. Note that the numbering scheme used for Great Britain does not include roads in Northern Ireland, which are allocated numbers on an ad hoc basis.
Great Britain.
Former motorways.
Roads which used to be motorways but have been downgraded:
Motorways under construction or planned.
The Adwick-le-Street to M62 stretch of the A1 is under consideration for upgrade to motorway standard, meaning the A1 between Blyth, south of Doncaster, to Birtley near Gateshead, would all be part of the same A1(M) stretch of motorway.
In addition, the proposal to put a tunnel under the River Thames to the east of Dartford Crossing and the revived Birmingham Western Orbital plans are both described as motorways.
Unbuilt motorways.
There have been many plans for motorways in the UK that have not been built. Below is a list of plans that were not built (not exhaustive):
Many cities had urban motorway plans, most of which were not built. London, Newcastle, Liverpool, Manchester/SELNEC and Glasgow all had extensive plans.
It was proposed that the A14 upgrade between Huntingdon and Cambridge would be classified as a motorway once complete, however prior to opening it was announced that the road would open as a "best in class A road" instead.
Northern Ireland.
Unbuilt motorways.
The following motorways were planned, but never built.
There were also urban motorway plans for Belfast