The Chatham-Kent census division, which includes the independent Delaware Nation at Moraviantown First Nation, had a population of 102,042 in the 2016 census.

In 1846, the town of Chatham had a population of about 1,500, with part of the town being called Chatham North. There were four churches, a theatre, a weekly newspaper and a cricket club. The road between London and Amherstburg was open, and transportation by stagecoach was available. A fast boat also provided transportation to Detroit and Buffalo. Chatham had many tradesman, a foundry, two banks, three schools, a tavern and a library where one could read books and newspapers.By 1869, the population was 3,000 in this industrial area with several mills, foundries, and breweries; a great deal of wood was being produced. A steamboat offered transportation to Windsor and Detroit. There was one bank office.

Between 1906 and 1909, the city was home to the Chatham Motor Car Company, and from 1919 to 1921, Denby Motor Truck Company of Canada. It was also where the Hyslop and Ronald steam fire engine manufacturer was located; the factory would be taken over by Chatham Motor Car. In addition, it hosted meat packer O’Keefe and Drew.