William Notman was a photographer born in Paisley, Scotland on 8 March 1826, the son of William Notman and Janet Sloan. Notman received some training as an artist, but joined his father's textile business rather than pursuing an artistic career. He migrated to Canada in 1856, fleeing allegations of fraud associated with the family business. He settled in Montreal and, after briefly working for a dry goods company, set up his own photography business. Despite having almost no professional experience, he quickly became an established photographer. In 1858, the Grand Trunk Railway awarded Notman a commission to photograph the construction of the Victoria Bridge.

In 1860, Notman hired artists John Arthur Fraser and Henry Sandham to run the company's art department, retouching, editing, and colouring prints, and painting elaborate studio backdrops. In 1864, the company had grown to 35 employees. As the company grew, a Toronto studio overseen by John Fraser was opened and styled "Notman & Fraser." Notman similarly recognized Sandham's contribution by offering him a junior partnership in 1871 and updating the Montreal studio's name to "Notman & Sandham." The company had at this point begun building an international reputation, with contracts to produce student and faculty portrairs at Vassar College, Harvard, and Yale. At its peak, in the 1880s, there were 20 different Notman studios.

Three of Notman's sons trained in photography and joined the family business. Notman's eldest son, William McFarlane Notman, became a name partner in 1882, and the company's name changed to "William Notman & Son." When Notman died in 1891, William took over leadership of the company. In 1913, William's younger brother, Charles, became head of the company, and held that role until 1935, when the company closed permanently. The company's collection was initially sold to Associated Screen News, but in 1957 it was purchased by McGill University, and it currently held at the McCord Museum of Canadian History.