He was born in Newton Stewart, Wigtownshire, the son of Andrew M’Douall. He served an apprenticeship with a surgeon in his home town, studied at Glasgow and Edinburgh, and in summer 1835 was admitted to the Royal College of Surgeons in Edinburgh. He subsequently moved to Lancashire, where he first managed a Burnley practice and then built up his own extensive and prosperous practice in the small cotton town of Ramsbottom. There he developed an intense interest in the medical effects of the factory system (he gave a British Association paper on the subject) and became involved in the ten-hour agitation. After his own arrest in December 1838, Joseph Rayner Stephens recommended M’Douall should take his place in the forthcoming Chartist convention as delegate for Ashton under Lyne, the militant Chartist centre with which M’Douall was to be closely associated for the rest of his life.
In the first convention in 1839, M’Douall was a foremost advocate of physical force and, later, of the ‘sacred month’. He was arrested in July 1839 while attempting to calm the crowd in the Birmingham Bull Ring, and the following month was sentenced at Chester assizes to twelve months’ imprisonment for sedition and attending an illegal meeting at Hyde in April. According to Gammage, he was ‘of an ardent fiery temperament, and though naturally possessing strong reflective powers, was impulsive to the last degree, and by no means deficient in the quality of courage’. ‘In stature M’Douall was rather short … in personal appearance he was decidedly handsome … his hair which was light, approaching to sandy … was parted in the centre, and hung in long graceful curls behind his ears, and his whole appearance was highly interesting’. For Adams he was a ‘picturesque figure … whose long cloak and general style helped to give him the appearance of a hero of melodrama’.
On his release in August 1840, M’Douall was fêted as he toured the north of England and Scotland; that year, or the following, while in Glasgow, he married Mary Ann, the daughter of a warder at Chester Castle, where he had served his sentence. An advocate of the organisation of Chartism in occupational groups, M’Douall played a prominent role in the recently formed National Charter Association, and headed the poll for the executive in both 1841 and 1842; he also published his own Chartist and Republican Journal in 1841. He stood for parliament at Northampton in June 1841 as a Chartist, but came bottom of the poll. After representing Ashton in the convention of April 1842, he was (with Thomas Cooper) the principal supporter of the general strike movement in August and it was he who drafted the executive’s very forceful address to the people. The government offered a £100 reward for his apprehension, but he escaped to France, where, sustained by Chartist collections, he lived for the next two years.
He was able to return to Britain without prosecution during 1844 and resumed the life of a Chartist agitator, publishing The Charter: What It Means! The Chartists: What They Want! (1845) and unsuccessfully contesting the parliamentary seat of Carlisle in June 1848. In 1848, he was a member of the national assembly and, once more elected to the executive, was at the heart of the first insurrectionary conspiracy of the summer. During the two years’ hard labour at Kirkdale gaol to which he was sentenced in August for his part in a meeting at Ashton, great hardship was suffered by his wife and children, the eldest of whom, a ten-year-old girl, actually died; and after release in 1850 his efforts to publish McDouall’s Manchester Journal and to establish a medical practice in Ashton both failed. The Northern Star had observed in 1848: ‘When he came among you he had good property in Scotland, a profession and a practice, which realized him several hundred pounds annually, besides a large sum of accumulated money in the bank. All of which has been spent long ago in the advocacy of the rights of the people.’
In the summer of 1853, M’Douall emigrated to Australia but he died shortly after arrival in ‘about May, 1854’. One apparently misleading story of several that circulated was that he had drowned in a shipwreck. After his death, M’Douall’s family returned to an uncertain future in England. As Harney was to recall, ‘no man in the Chartist movement was better known than Dr McDouall’. He was one of the half-dozen outstanding leaders of Chartism.
 P. Pickering and S. Roberts ‘Pills, pamphlets and politics: the career of Peter Murray McDouall (1814–54)’, Manchester Region History Review, volume 11, (1997), pages 34-43, R. Challinor ‘Peter Murray McDouall and “physical force Chartism”‘, International Socialism, volume 12, (spring 1981), pages 53-84 · P. M. M’Douall The charter: what it means! The chartists: what they want!, 1845, ‘Portraits of delegates, no. 6’, The Charter, 7th April 1839, R. G. Gammage History of the Chartist movement, 1837–1854, new edition, 1894, ‘Vicissitudes of a chartist leader’s family’, Daily News, 5th August 1856, Q., letter, Newcastle Weekly Chronicle, 8th March 1884, W. E. Adams Memoirs of a social atom, 2 volumes, 1903, W. H. Maehl, (ed.) Robert Gammage: reminiscences of a chartist, 1983, G. J. Harney, ‘Acknowledgements’, Newcastle Weekly Chronicle, 27th February 1897 and ‘Dr. P. M. M’Douall’, Star of Freedom, 17th July 1852
 R. G. Gammage History of the Chartist movement, 1837–1854, new edition, 1894, pages 66-67.
 W. E. Adams Memoirs of a social atom, 2 volumes, 1903, volume 1, pages 211-212.
 Quoted in R. Challinor ‘Peter Murray McDouall and “physical force Chartism”‘, International Socialism, volume 12, (spring 1981), pages 80-81.
 Newcastle Weekly Chronicle, 8th March 1884.