John McMillan (August 4, 1816 – September 12, 1886) was a New Brunswick businessman and political figure.
He represented Restigouche in the House of Commons of Canada as a Liberal member from 1867 to 1868.
McMillan worked at the timber trade and later with a partner established a lumber firm and a general store at Campbellton.
In 1857, he was elected to the Legislative Assembly of New Brunswick for Restigouche County; he was reelected in 1861, 1865 and 1866.
He was elected to the House of Commons in 1867 but resigned in 1868 to become Inspector of Post Offices for the province.