"Cowichan Harbour (not Cowichin nor Cowitchin)" adopted in the 7th Report of the Geographic Board of Canada, 30 June 1908. Form of name changed to Cowichan Bay 8 October 1924, as labelled on Trutch's 1871 map of British Columbia, and on BC map 2A, 1913.

Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office

Labelled "Cowitchin Harbour" on British Admiralty Chart 2840, 1861 et seq.

Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office

"Named c1850 by the officers of the Hudson's Bay Company... This name was given in the early days of the colony of Vancouver Island and is that of an important tribe of Indians who then resided in the vicinity in large numbers. It first appears on the early plan to accompany the "Report of a Canoe Expedition along the East Coast of Vancouver Island: by James Douglas, Esq, Governor, 1854." and is given in the text as Cowichin... The waters on the east coast of Vancouver Island, inhabited by the small bands which together were known as the powerful Cowichan tribe, teemed with edible fish, and on the land deer and fur-bearing animals abounded, which afforded the natives with an easy and convenient means of providing their daily food.... [The] natural wealth of the country led to a division of the Cowichans into small bands such as those known in the present day as Saanich, Somenos, Quamichan, Koksilah, Chemainus, Lamalchi and Penelakut, all derived from the bands of the great Cowichan tribe... It is recorded that [Simon] Fraser on his arrival at the mouth of what is now the Fraser River, in 1806, [had been] warned by the [Indigenous People] of that neighbourhood of a fierce tribe known as the Ka-way-chin residing between that river and the main ocean. Doubtless the Cowichan Indians." According to Walbran the name means "between streams".

Source: Walbran, John T; British Columbia Coast Names, 1592-1906: their origin and history; Ottawa, 1909 (republished for the Vancouver Public Library by J.J. Douglas Ltd, Vancouver, 1971)

After a group of Salish tribes occupying the southeast coast of Vancouver Island. Cowichan means "sunny side" or "basking in the sun" (Report of Cowichan Historical Society, published in the Cowichan Leader 22 February 1934). See Cowichan River for additional information.

Source: BC place name cards, or correspondence to/from BC's Chief Geographer or BC Geographical Names Office

The bay was named about 1850 by officers of the Hudson's Bay Company for the powerful Coast Salish First Nation - the most populous in BC - that occupies this territory (and now spells its name Quw'utsun'). Cowichan Lake, Cowichan Station, the Cowichan Valley Regional District, etc, all derive their names from the same name source. Cowichan is an adaptation of an Island Halkomelem term for "warming the back," which, in turn, refers to a bare, rocky formation on the side of Mount Tzouhalem, said to look like a frog sunning itself. There were many variants of this name in the old days, includeing Cowichin, Cowitchin, Cowitchan, K'au'itchin and Ka-way-chin. The earliest version recorded probably that of the Hudson's Bay Company trader John Work, who mentioned the Coweechin in 1824. In fact, so many Quw'utsun' people migrated across the Straights of Georgia each year to occupy summer village sites on the Fraser and harvest its great salmon runs that Work identified that river as the Coweechin. The Songhees First Nation name for Cowichan Head, the northern boundary of their territory, was Tiumalatchung.

Source: Scott, Andrew; "The Encyclopedia of Raincoast Place Names"; Harbour Publishing, Madeira Park, 2009, pp. 137-138.