In relation to natural increase or inter-provincial migration, immigration is a huge population growth force in Ontario, as it has been over the last two centuries. More recent sources of immigrants with already large or growing communities in Ontario include Caribbeans (Jamaicans, Trinidadians, Guyanese, and Bajan), South Asians (e.g. Pakistanis, Indians, Bangladeshis and Sri Lankans), East Asians (mostly Chinese and Filipinos), Latin Americans (such as Colombians, Mexicans, Hondurans, Argentinans, and Ecuadorians), Eastern Europeans such as Russians and Bosnians, and groups from Somalia, Iran, and West Africa. Most populations have settled in the Greater Toronto area. A smaller number have settled in other cities such as London, Kitchener, Hamilton, Windsor, Barrie, and Ottawa.

Ontario is the second most diverse province in terms of visible minorities after British Columbia, with 22.8% of the population consisting of visible minorities.[26] The Greater Toronto Area, Ottawa, Windsor, Hamilton and Waterloo Region are quite diverse metropolitan areas.

Aboriginal peoples make up 2% of the population, with two-thirds of that consisting of North American Indians and the other third consisting of Métis. The number of Aboriginal people has been increasing at rates greater than the general population of Ontario.