General William Carr Beresford, 1st Viscount Beresford, 1st Marquis of Campo Maior, (; 2 October 1768 – 8 January 1854) was an Anglo-Irish soldier and politician. A general in the British Army and a Marshal in the Portuguese Army, he fought alongside The Duke of Wellington in the Peninsular War and held the office of Master-General of the Ordnance in 1828 in Wellington's first ministry. He led the 1806 failed British invasion of Buenos Aires