Wallington was an ancient hundred in the northeast of the historic county of Surrey, England. The majority of its area has been absorbed by the growth of London; with its name currently referring to the district of Wallington. Its former area now corresponds to the London Borough of Sutton, the majority of the London Borough of Croydon and parts of the London Borough of Merton as well as parts of the Districts of Epsom and Ewell, Reigate and Banstead and Tandridge in Surrey.