The A103 is an A road in London, England.

It runs from Lower Holloway to Hornsey and includes Hornsey Road, Hornsey Rise, Crouch End Hill, Broadway Parade, Tottenham Lane, before ending in Church Lane, Hornsey.

It head northeastwards and almost immediately comes to a roundabout with some unclassified roads by the Arsenal stadium and veers left, under a long railway bridge over which runs the main line to King's Cross and which is always plastered with fly-posters, and over two separate sets of traffic lights with the A503, which is in a one-way system at this point. Past those and up the hill, one sees Hornsey Baths and a cop shop on your right before more traffic lights at the junction of Tollington Park and Hanley Road.

The hill steepens to the point of getting a lot into the traffic and being stuc behind public transport until it finally flattens out at the top of Hornsey Rise at the junction with the B540 Hornsey Lane, well worth a detour for the road fan as this is the road which goes across the celebrated Archway.

The northern end of this road is called Tottenham Lane but actually it is Arsenal whose stadium (Emirates Stadium, originally Highbury Stadium) it will go past at the other end.

With an average speed of 5.9 mph, the A103 is the 4th slowest road in the country.

The road crosses the route of the former Seven Sisters to Alexandra Palace railway line.

51°34′13″N 0°07′27″W / 51.5704°N 0.12409°W / 51.5704; -0.12409