Named after Wanstead Park, once the grounds of the grand Wanstead House.
Sir Richard Child had the mansion built in 1715–1722 to rival houses such as Blenheim Palace. After the heiress Catherine Tylney-Long married the spendthrift William Wellesley-Pole, its contents were auctioned in 1822 and the house was demolished in 1825; its gardens are now the park. Planned as Forest Gate, the station does lie in Forest Gate – near Wanstead Flats, not the park.