Lieutenant Colonel Rupert Charles Ponsonby, 7th Baron de Mauley (born 30 June 1957), is a British hereditary peer, former Parliamentary Under-Secretary at the Department for Environment, Food and Rural Affairs and retired Territorial Army officer.

Thomas Maurice Ponsonby (1930–2001) of The Common, Little Faringdon, Lechlade, late Royal Wessex Yeomanry, High Sheriff of Gloucestershire, and his wife Maxine Henrietta (née Thellusson, 1934–2020), daughter of William Dudley Keith Thellusson, of 39, Draycott Place, SW3,[2][3][4] of the Brodsworth Hall branch of the family of the Barons Rendlesham.

On 10 March 2005, he was declared the winner of a by-election for a Conservative hereditary peers' seat in the House of Lords after the death of Hugh Lawson, 6th Baron Burnham.

His roles there included resource management, the local environment, environmental science and the department's work with small and medium-sized enterprises.

[17] His selection in 2014 to lead UK fisheries talks in the European Union faced certain criticism, given his background as a hereditary peer with no prior experience in this field.