Rupert Charles Ponsonby, 7th Baron de Mauley TD FCA (born 30 June 1957) is a British hereditary peer, Parliamentary Under-Secretary at the Department for Environment, Food and Rural Affairs and retired Territorial Army officer.
Ponsonby was educated at Eton College, an independent school for boys near Windsor, Berkshire.
Lord de Mauley succeeded his uncle, the 6th Baron de Mauley, in October 2002. On 10 March 2005 he was declared the winner of a by-election for a Conservative hereditary peers' seat in the House of Lords. He was the first peer to have acceded to a title after the House of Lords Act 1999 to have obtained an elective hereditaries' seat in the House.
He is currently Parliamentary Under-Secretary at the Department for Environment, Food and Rural Affairs after taking over from John Taylor, Baron Taylor of Holbeach, who went to the Home Office. He was previously a Government Lord-in-Waiting (a position in the Royal Household given to Government Lords whips) and also served as a Shadow Minister for Children, Schools & Families and Energy & Climate Change from 2008 to 2009, and then an opposition whip from 2009 to 2010.
His brother, Ashley George Ponsonby, was allowed by a Warrant of Precedence from the Queen to use the style of Honourable, because his father would have held the peerage but for his predeceasing the previous holder.