Copper Cliff is a community and former company town in Greater Sudbury, Ontario, Canada. Incorporated in 1901, Copper Cliff was a separate municipality until it was annexed by the City of Sudbury in 1973 as part of the creation of the Regional Municipality of Sudbury. The ore was initially shipped to a smelting plant in Constable Hook, New Jersey, where it was discovered that the ore was rich in nickel. Large-scale nickel mining began in 1902 with the formation of the International Nickel Company backed by American banker J.P. Morgan and Charles Schwab. Conversely, many immigrant workers such as Poles, Finns, Italians, and French Canadians worked in a less developed area of the city just south of the mine often referred to as "Shantytown" because of the quantity of shacks and shanties present. A ceremony was held by residents on 31 December 1972 to mourn the loss of the town. Some residents opposed the merger, and had formed a committee to oppose it.
The operations of the sintering plant in Copper Cliff that ran from 1948 to 1963 produced large amounts of nickel sulphide and sulphur dioxide that served as a significant health risk at the time to the workers at the plant and the local community. Workers that were exposed to the dust without proper protective equipment were victim to various forms of respiratory cancers, which led to an abnormally high mortality rate within the province. The Superstack was decommissioned in 2020. The superstack was constructed because of pressure from the local community and provincial government with the goal of dispersing the toxic emissions into the atmosphere to improve the air quality of Copper Cliff. Outside the community, the superstack is seen as a symbol of pollution, however the superstack holds deep meaning for the community of Copper Cliff. A number of Italian-Canadians in Copper Cliff trace their heritage to the Italian town of Metaurilia in the Pesaro e Urbino commune of Fano.
Little Italy arose from the creation of a smelter by Inco leading to an influx of Italian immigrants in the area. Little Italy quickly became a ghetto for the Italian community reinforced by an Italian church, and Italian stores and services, which kept the community close and uneager to visit sections of Copper Cliff that did not have an Italian presence. When Italy entered the war on June 10, 1940, several hundred Italian Canadians living in Sudbury were considered "enemy aliens" and put into work camps.