Watford is a station at the end of the Watford branch of London Underground's Metropolitan Line in the north-western part of the network in Zone A . It is in the Cassiobury area of Watford, opposite the park. It is known locally as "Watford Met". The station building is typical red-brick and was designed by C. W. Clark.

Watford station opened on November 2, 1925, as part of the extension of the line from Moor Park, with electrical supply from the Metropolitan Railway, and a train service from the Great Central Railway to London Marylebone operating in the first few months. Although it is the terminus of the branch it was not planned as such, with an extension to the town centre envisaged but never constructed. Nevertheless, for many years a bus service ran from the station to the high street, greatly increasing patronage of the line.

For many years a short branch line from Watford Junction ran to nearby Croxley Green , though passenger usage was low. In 1996 rail services were withdrawn and the line allowed to fall into disuse. The line comes very close to the Metropolitan Line south of Watford and it has often been proposed to build a short flyover to link the two lines to create a through route to Watford Junction. This would lead to the closure of Watford Met, but Watford West station could be given a new exit to provide a near enough service.

It is envisaged that the services on the lines so linked could be further enhanced by using the north-facing junction on the Metropolitan main line north of Moor Park to provide shuttle services between Watford Junction and Amersham, Chesham or even Aylesbury. It is believed that such a service would do much to enhance the entire area.

This project, although small, has long faced problems with funding. As Watford is outside Greater London, normal sources of funding for the Tube are not available. Hertfordshire County Council do not have railways within their remit and so are unable to supply the funding on their own. However, the County Council, backed by Transport for London, are now leading a combined scheme to build the extension largely from a Government grant; this is projected to cost about £60m, and give completion by 2009. It remains to be seen whether these funds will be forthcoming.

In earlier days the station was in Zone B, but in 2004 the station has been included in Travelcard Zone A.