Viscount Allenby, of Megiddo and of Felixstowe in the County of Suffolk, is a title in the Peerage of the United Kingdom. It was created on 7 October 1919 for the prominent military commander Field Marshal Sir Edmund Allenby, with remainder, in default of male issue of his own, to his younger brother Captain Frederick Claude Hynman Allenby and his heirs male lawfully begotten. The first Viscount's son was killed in action on the Western Front in 1917.

He was succeeded according to the special remainder by his nephew, the second Viscount. The latter's son, the third Viscount, who succeeded in 1984 was one of the ninety elected hereditary peers that remain in the House of Lords after the passing of the House of Lords Act 1999, and sat as a crossbencher. As of 2017, the title is held by his son, the 4th Viscount, who succeeded in 2014.

The family seat is Newham Lodge, near Hook, Hampshire.