The A1 in London is an A road in North London. It runs from the London Wall to Bignall's Corner, where it crosses the M25 motorway and becomes the A1(M) motorway, continuing to Edinburgh. The London section passes through four London boroughs: the City of London, Islington, Haringey and Barnet. Whilst the route of the A1 outside London closely follows the historic route of the Great North Road, the London section for the most part does not.

The current route of the London section of the A1 road was mainly designated as such in 1927. It comprises a number of historic streets in central London and the former suburbs of Islington, Holloway and Highgate and long stretches of purpose-built new roads in the outer London borough of London Borough of Barnet, built to divert traffic away from the congested suburbs of Finchley and High Barnet.

The London section of the A1 is one of London's most important roads. It links North London to the M1 motorway and the A1(M) motorway, and consequently serves as Central London's primary road transport artery to the Midlands, Northern England and Scotland. It also connects a number of major areas within London, and sections of it serve as the High Street for many of the now-joined villages that make up north London. (Full article...)