William Waldorf Astor III, 4th Viscount Astor (born 27 December 1951) is an English businessman and politician who sits as a Conservative hereditary Lord Temporal in the House of Lords.

In 1994, he moved to the Department of National Heritage where he served until leaving the government in 1995.

He was a member of the Founding Council of the Rothermere American Institute at the University of Oxford.

[1] Viscount Astor is Chairman of Silvergate Media and director of Networkers Plc (since 2007) and trustee of Stanley Spencer Gallery in Cookham.

[3] His wife Annabel's stepfather was his uncle Michael Langhorne Astor.