The first station at the site was Willesden which was opened in 1841 by the London and Birmingham Railway and closed in 1866, replaced by Willesden Junction station, 0.5 miles (0.80 km) to the south east. In the Watford DC Line program of new electrified suburban tracks of the London and North Western Railway, a new station, "Harlesden", opened on 15 June 1912. Bakerloo line services on the same tracks began on 16 April 1917, via a new junction at Queens Park station. The Watford Junction to Euston modernisation project was completed in 1922. It should not be confused with Harlesden (Midland) railway station, which closed to passengers in 1902 and was nearby on the Dudding Hill Line.
In the 19th century, Harlesden, then a rural village, began to develop some of its urban appearance with the arrival of the railways. Willesden Junction, Kensal Green and Harlesden stations all had an effect on the developing village. Cottages for railway and industrial workers were built, as was grander housing for the local middle class. Harlesden increasingly lost its rural nature, with factories replacing farms and woodland. From late Victorian times until the 1930s, housing completed its spread across the area, and Harlesden became part of the London conurbation. Mainly after World War I, one of Europe's biggest industrial estates was constructed at nearby Park Royal, and large factories there included McVitie & Price (later United Biscuits) from 1910, and Heinz from 1919. The station has wi-fi, a bridge and help points but no toilets.
Connections: Bakerloo Line. London bus routes 187, 206, 224, 226, 228, 260 and 487 serve the station.