Charles Vane, 3rd Marquess of Londonderry, Irish soldier and diplomat, British Ambassador to Austria (d. 1854)
Charles William Vane, 3rd Marquess of Londonderry, (born Charles William Stewart; 1778–1854), was an Anglo-Irish nobleman, British soldier and politician. He served in the French Revolutionary Wars, in the suppression of the Irish Rebellion of 1798, and in the Napoleonic wars. He excelled as a cavalry commander in the Peninsular War under John Moore and Arthur Wellesley (the later Duke of Wellington).

On leaving Wellington's command, his half-brother Lord Castlereagh helped him to launch a diplomatic career. He was posted to Berlin in 1813, and then as Ambassador to Austria, where his half-brother was the British plenipotentiary at the Congress of Vienna.

He married Lady Catherine Bligh in 1804 and then, in 1819, Lady Frances Anne Vane, a rich heiress, changing his surname to hers, thus being called Charles Vane instead of Charles Stewart from there on. In 1822 he succeeded his half-brother as 3rd Marquess of Londonderry, inheriting estates in the north of Ireland where, as an unyielding landlord, his reputation suffered in the Great Famine. It was a reputation he matched as a coal operator on his wife's land in County Durham. In opposition to the Mines and Collieries Act of 1842, he insisted on his right to employ child labour.