John Angus Macsween (17 October 1939 – 12 July 2006) was a Scottish butcher and entrepreneur who helped popularise haggis as an international dish.^[1][2][3][4]

Macsween came from a family of butchers in Edinburgh, where he noted the popularity of haggis among English rugby fans attending international matches at Murrayfield Stadium.^[1] After taking over the family business in 1975, the subsequent popularity of their haggis led to his opening the world's first purpose-built haggis factory, and the sale of the butchers company.^[1][5] In the 1970s Macsween took samples to London, and soon received orders for Macsween haggis from major buyers including Selfridges, Harrods, and Fortnum & Mason.^[1][5]

Macsween started to produce what was described as a vegetarian haggis in 1984, after a request from the Burns Supper at the Scottish Poetry Library.^[1][5] It is stated that this was the first vegetarian haggis produced and available commercially.^[3]

Macsween was the eldest of three siblings and attended James Gillespie's High School and George Heriot's School.^[2]

Macsween married Kate Mackay, the daughter of James Wilson McKay, who became Lord Provost of Edinburgh, in 1964.^[5] His wife and his four children survived him at this death,^[1] and Macsween haggis continued to be produced,^[6] sold under both the Macsween name and as supermarkets' own brands.^[7]

He also had an interest in horticulture.^[2]