"Tanoo Island" adopted 7 March 33, as listed in the 1930 Gazetteer of Canada and as labelled on BC Land's Map 2F, 1927. "Tanu Island" adopted 3 July 1946 on Map 103SE, "Queen Charlotte Islands to Bella Bella," as establised on Hydrographic Services Chart #370. Tanu is derived from the Haida word for "eel-grass."

Source: BC place name cards & correspondence, and/or research by BC Chief Geographer & Geographical Names Office staff, file Q.1.45.

Geologist George M Dawson named the island Tanoo in 1878, after the famous Eagle crest village on its eastern shore. While the preferred spelling today is T’aanuu, the variants Tannu, Tahnoo, and Tanoo have all been widely used in the past. The word can be translated as “sea grass” or “eelgrass” and refers to the subtidal plants that grow near the village site. Tanu was also known as Klue’s village, after the hereditary name of the powerful and influential town chief (see Klue Passage). “When we visited the village,” wrote Dawson, “we found it to be the most flourishing of any of the Charlottes. Sixteen well-built lodges ring the shoreline and 30 finely carved poled proclaim the artistry of its residents.” HBC officer John Work counted 545 people there in 1840. In 1887, after the ravages of TB and smallpox had reduced the population to 80, the remaining inhabitants moved to New Kloo on the N end of Louise Island. Page 582-583.

Source: Scott, Andrew; "The Encyclopedia of Raincoast Place Names"; Harbour Publishing, Madeira Park, 2009, page 582-583.