In the early 20th century, the Metropolitan Railway (MR) penetrated Hertfordshire and Buckinghamshire with its suburban railway, enticing Londoners with its "Metro-Land" advertising campaign promoting the new railway as an opportunity to live in a rural location with easy transport to central London. The MR was also intent on providing a connection from Watford and planned a branch line from Moor Park via Croxley. The MR purchased a swathe of land from Gonville and Caius College, Cambridge along the planned route and Parliamentary approval for the branch was granted in 1912. The project was hampered by disagreements with the Watford Borough Council and by the outbreak of World War I in 1914, and construction of the 2.5-mile (4.0 km) branch did not begin until 1922. Watford Met station opened on 4 November 1925, with MR electric trains to Baker Street and LNER steam trains to Marylebone for the first few months.
The station suffered from its distance from the town centre. For many years, the MR operated a bus service from the High Street in an effort to gain more passengers, but contrary to the Watford Observer's predictions patronage remained low. MR passenger numbers compared unfavourably with services into central London offered by the LMS and the UERL Bakerloo line from Watford Junction and Watford High Street, and after the General Strike of 1926 the LNER pulled out of the venture with the MR. The station building was designed by the Metropolitan Railway's architect Charles Walter Clark in an Arts and Crafts vernacular style. It is in red brick with a clay-tiled hipped roof, tall brick chimney stacks, and timber sash and casement windows. The main entrance is covered by a polygonal metal canopy supported by twin Doric columns, and the interior, mostly unaltered from the original, is decorated with period tiling and hardwood panelling. The station building is grade II listed. The station has cash machines, Euro cash machines, help points, toilets, a car park, payphones and a waiting room.
Connections: The station is served by the W30, R4, 320 (Arriva) and 324 (Arriva) bus routes.