The Cowichan Valley Regional District is a regional district in the Canadian province of British Columbia that is on the southern part of Vancouver Island, bordered by the Nanaimo and Alberni-Clayoquot Regional Districts to the north and northwest, and by the Capital Regional District to the south and east. As of the 2021 Census, the Regional District had a population of 89,013. The regional district offices are in Duncan.

The Regional District of Nanaimo is a regional district located on the eastern coast of Vancouver Island, British Columbia, Canada. It is bordered to the south by the Cowichan Valley Regional District, to the west by the Alberni-Clayoquot Regional District, and to the northwest by the Comox Valley Regional District. Its administration offices are located in Nanaimo. During the 2016 census, its population was established at 155,698.