Balfour was a successful architect in Hamilton, Ontario, during the last two decades of the 19th Century. His father, Peter Balfour, was a native of Fifeshire, Scotland, who settled in Hamilton in 1842, and who commenced practice as a builder, carpenter and joiner; he later served as city alderman and assessment commissioner.

James Balfour was born in Hamilton on Dec. 24, 1854, and was educated there at Central School, but left Canada at the age of 18 to apprentice with the prominent Scottish architectural partnership of Peddie & Kinnear in Edinburgh. He then moved to New York City for a year, and returned to Hamilton to open an office in late 1873.

Assimilating the popular Second Empire style, he quickly established himself as a competent designer of residential and commercial buildings in the Hamilton area, and took frequent advantage of numerous architectural competitions held in Canada and the United States to obtain commissions. He won First Prize for his impressive design of Alma College, St. Thomas (1878; burned 2008), for the Hamilton City Hall (1887) and for the Detroit Museum of Art (1887), all of which were realized as originally conceived. He also won competitions for the St. Thomas Post Office (1882) and the Oxford County Court House (1889), but neither project was built for a variety of financial and political reasons.

By 1885, his designs were drawing inspiration primarily from the American architect Henry H. Richardson, the most skilled proponent of the Romanesque Revival style in the United States from 1870 until his death in 1886, and this influence is apparent in Balfour's work well into the 1890s.

He was an active member of the Ontario Society of Artists and an associate of the Royal Canadian Academy. Balfour was not a theorist, however, although his brief essay entitled "Architecture in Canada" (C.A.B., iii, June 1890, 3) does give some insight into the state of architectural design in this country through the eyes of a prolific and technically competent practitioner. Balfour's consistency of style and architectural ingenuity in his later work appear to have impressed Hamilton City Councillors when they awarded him First Prize in the competition for the City Hall in Hamilton in 1887 (Spectator [Hamilton], 13 Aug. 1887, 4). This accomplished design for a dignified Romanesque work executed in Port Credit sandstone was selected over the design prepared by his rival Charles W. Mulligan, and became the crowning achievement of his career upon its completion in 1889. That same year, he was declared the winner of the competition in February 1887 for the new Art Museum in Detroit, Michigan (Detroit Free Press, 1 Feb. 1887, 8; 3 Feb. 1887, 5; 4 Feb. 1887, 8). This victory was not without criticism and debate, as the eminent jurors who selected the design were interviewed at great length and revealed their lack of support for Balfour's design (Detroit Free Press, 12 March 1887, 5, descrip.).

Balfour was married to Georgina Catharine Munro on June 26, 1878, and they raised five children before their marriage ended in a highly publicized divorce case when she was accused of adulterous behaviour and she in turn claimed Balfour had been "...violent, obscene and abusive" (Spectator [Hamilton], 25 May 1892, 1; 1 June 1892, 1; 29 June 1892, 1).

A long illness prevented Balfour from carrying out significant work after 1905, and he died at Hamilton on April 10, 1917, and was buried at Hamilton Cemetery.