Sir John Macartney, 1st Baronet (died 29 May 1812) was an Irish Member of Parliament.
He was the second son of William Macartney, a long-serving Member of Parliament for Belfast, by his wife Catherine, daughter of Thomas Bankes.
He married firstly (by licence of the prerogative court of Ireland dated 26 February 1778) Anne, daughter of Edward Scriven by his wife Elizabeth, daughter of John Barclay of Dublin.
Macartney married secondly on 4 November (by licence dated 3 November) 1794, Catherine, daughter of Walter Hussey Burgh, late Chief Baron of the Exchequer of Ireland, by his wife Anne, daughter of Thomas Burgh of Bert, County Kildare.
On 29 April 1796, at the opening of the Grand Canal Docks, he was knighted "in consequence of his energetic exertions in the promotion of the inland navigation of Ireland", and on 4 January 1799 (the privy seal being dated 25 June 1799), he was created a baronet, of Lish, County Armagh.