Rear Admiral John Townshend, 4th Marquess Townshend (28 March 1798 – 10 September 1863), known as John Townshend until 1855, was a British nobleman, peer, politician, and naval commander.
Townshend was the son of Lord John Townshend, younger son of George Townshend, 1st Marquess Townshend. His mother was Georgiana Anne Poyntz. He served in the Royal Navy and achieved the rank of Rear-Admiral. Between 1847 and 1855 he also sat as a Member of Parliament (MP) for Tamworth. In the latter year he succeeded his first cousin in the marquessate and entered the House of Lords.