Sir John Johnstone, 6th Baronet

Sir John Lowther Johnstone, 6th Baronet (1783–1811) was a British Army officer and politician.

Life He was the son of George Johnstone, who died in 1787, and his wife Charlotte Dee. His mother married again, in 1790, to Charles Edmund Nugent.

Johnstone was brought up in the expectation of inheriting from his paternal uncle, the wealthy Sir William Pulteney, 5th Baronet, a property developer who died in 1805, and who had changed his surname from Johnstone. He left one child, Laura Pulteney, 1st Countess of Bath, who died in 1808. In consequence of his uncle's death, Johnstone became 6th Baronet, and inherited a Scottish estate in Dumfriesshire. There was much interest in the 1806 contest. Patrick Miller, who had ten years before broken with his patron William Douglas, 4th Duke of Queensberry and joined the Whig Club, contacted Charles James Fox about it. Sir John Heron Maxwell, a Tory passed over in 1804, might have run and split the vote. Johnstone had backing from Lord Grenville, James Maitland, 8th Earl of Lauderdale and William Adam of Blair Adam. It was enough to make a contest of it, but no more, Johnstone losing by 26 votes to 34. He undertook to stand again, and had the chance in the 1807 general election, but did not on that occasion. One of its members, Gabriel Tucker Steward, resigned from parliament in 1810, giving Johnstone a chance to stand as replacement. Johnstone made an uncontested entry into parliament in June of that year.

The History of Parliament and a contemporary newspaper account state that Johnstone died on 24 December 1811, the latter giving the place of death as Baker Street, London. According to The History and Antiquities of the Borough and Town of Weymouth and Melcombe (1829) by George Alfred Ellis, Johnstone died of delirium tremens in the House of Commons, on 19 March 1811.

Family Johnstone married Charlotte Gordon, daughter of Charles Gordon of Cluny, Aberdeen. When Alexander Gordon of Tobago died in 1801, he left monetary legacies to the three daughters of Charles Gordon, his nieces, and two of the sons, John and Alexander, received compensation money for the enslaved people on his Tobago estates in 1839.

The History of Parliament states that Johnstone's marriage was in 1804. Charlotte Margaret, married in 1831 Rev. Henry William Buckley Anne Elizabeth, married in 1830 Edmund Hiley Bucknall Estcourt, and was mother of George Sotheron-Estcourt, 1st Baron Estcourt.

After Johnstone's death, his estates were put in the hands of trustees (the Duke of Cumberland, Viscount Newark, Masterton Ure and David Cathcart); who also acted as legal guardians to his children. Charlotte wrote in 1812 to James Brougham, referring particularly to the Weymouth constituency, and explaining that it completely cut out any influence she might have on candidates. The daughter Elizabeth married in 1844 James Grimston, 2nd Earl of Verulam.