Sir John Jennings (1664 – 23 December 1743) was a Royal Navy officer and Whig politician who sat in the English and British House of Commons between 1705 and 1734. He commanded HMS Kent at Cadiz and Vigo in 1702 during the War of the Spanish Succession. He went on to be Commander-in-Chief of the Jamaica Station, then Senior Naval Lord and finally Governor of Greenwich Hospital.