New North Main Line

The Acton–Northolt line (ANL), historically known as the New North Main Line (NNML), is a railway line in west London, England. Built between 1903 and 1906, it runs from the Great Western Main Line at Old Oak Common TMD to the Chiltern Main Line at South Ruislip, alongside the West Ruislip branch of the London Underground Central line, for a distance of around 11 miles (18 km). At present, it is little used.

It opened in 1903 as part of a joint project by the Great Central Railway (GCR) and the Great Western Railway (GWR) to improve their termini's access from London to the Midlands and North of England, especially relative to the London and North Western Railway (LNWR). It begins at Old Oak Junction on the Great Western Main Line from Paddington and runs via Greenford to join what is now the Chiltern Main Line at Northolt Junction, southeast of South Ruislip.

The line joined the Great Western and Great Central Joint Railway between West Ruislip and Denham station in 1906. Its original name was "Denham – Junction for Uxbridge" as it was planned to be a stop on the shuttle service between Gerrards Cross and Uxbridge High Street. The latter was closed in 1964 and later demolished.