James Duncan and Andrew Duncan were merchants in Charlottetown, Prince Edward Island, who became partners in shipbuilding in the mid-1830s. They sold 15 ships jointly in the period from 1835 to 1840. Although the partners appear to have eventually gone their separate ways, with Andrew Duncan becoming a partner in Duncan, Mason and Company, and James Duncan founding a company in his own name, they possibly maintained business ties. In addition to building and selling ships, both companies retained vessels for cargo hauling purposes. The trade in ships and goods between Prince Edward Island and Great Britain was brisk in the mid-1800s and those in the business flourished. However, by the 1870s a turnaround had begun, culminating in the bankruptcy of James Duncan and Company in October of 1878. So influential was the company to the Island economy that it sent the province's shipbuilding sector into a steep decline from which it never recovered.

Andrew died in Liverpool, England, in 1872, while James died 11 June 1889 in Scotland. It is uncertain if there were familial ties between the two men.