Born in Dornal, Scotland, Neilson arrived in Quebec City, Lower Canada in 1791 to work for his uncle's printing company, which he inherited in 1793. Elected to the Legislative Assembly of Lower Canada in a partial election in 1818, he was re-elected until 1830 and supported the Parti canadien. In 1823, he accompanied Louis-Joseph Papineau to London to lobby against the Union project in the name of the majority of the MPs in the Legislative Assembly of Lower Canada. Again, in 1828 he was part of a delegation sent to London (UK) to present his party's demands for reform. In 1830, he took his distance from the Parti patriote, which he considered to be too radical. He opposed the Ninety-Two Resolutions of 1834, a rewrite of the 1828 demands for reform with a radical tone. In 1837, he was named to the Executive Council and Legislative Council; Nielson was a member of the Special Council that administered Lower Canada after the Lower Canada Rebellion.
He opposed the Union after its enactment. In 1841, he was elected to the 1st Parliament of the Province of Canada in the riding of Quebec County. He was elected speaker, but in 1844 was appointed to the Legislative Council.
He died at Cap-Rouge in 1848.
- Aux electeurs du comté de Quebec/To the Electors of the County of Quebec, 1820
- Letter from L.J. Papineau and J. Neilson, Esqs., Addressed to His Majesty's Under Secretary of State on the Subject of the Proposed Union of the Provinces of Upper and Lower Canada., 1823 (online)
- Report of the Special Committee of the House of Assembly of Lower-Canada, on the Petitions Against the Road Laws and the Office of Grand-Voyer, 1830
- Rapport du Comité spécial de la Chambre d'assemblée sur le Département du bureau de la poste dans la province du Bas-Canada, 1831
- Report of the Commissioners Appointed under the Lower Canada Act, 4th William IV. cap. 10, to Visit the United States' Penitentiaries, 1835
- First report. The Select Committee Appointed to Investigate and Report on the Outrages Alleged to Have Been Committed at the General Election in the Counties of Terrebonne, Montreal, Vaudreuil, Beauharnois, Chambly and Rouville, 1843
- Samuel Neilson (1800-1837)
- William Neilson (1805-1895) married Margaret Cassin
- John Jr. Neilson (1820-1896) married Laura Moorehead
- Isabel Neilson (1798-1873)
- Mary Neilson married notary Thomas Lee
- Elisabeth Neilson (1804-1804)
- Margaret Neilson (1808-1894)
- Janet Neilson (1810- )
- Agnes Janet Neilson (1815-1837)
- Frances Neilson (1815- )
One of his granddaughters Isabel Neilson married Charles Stuart Wolff the son of Lt. Col. Alexander Joseph Wolff a British soldier who established in Valcartier, Canada in 1824.
- "John Neilson". Dictionary of Canadian Biography (online ed.). University of Toronto Press. 1979–2005.
- "Biography". Dictionnaire des parlementaires du Québec de 1792 à nos jours (in French). National Assembly of Quebec.
- Tomlinson, James (1972). L'imprimerie Neilson, Montréal: Université de Montréal, 23 p.
- Audet, Francis-Joseph. "John Neilson", in Mémoires de la société Royale du Canada. Troisième Série; Vol. XXII, Ottawa, 1928, p. 81-97