Canton Alley, twin to Maynard Alley a block to the west, is another one of the few named alleys in Seattle. It goes just under ⅕ of a mile from S King Street in the north to S Dearborn Street in the south, between 7th Avenue S and 8th Avenue S.
Similar to the one in Vancouver, British Columbia, it was named after the city and province of Canton in China, today known as Guangzhou in Guangdong province, from where the majority of Chinese immigrants to Seattle came.
As with Maynard Alley, even though Canton Alley had been called that for years, and was signed as such, its name was not officially made Canton Alley S until 2019, so that addresses from which 911 calls were coming could be more easily located and emergency vehicle response times could be reduced.
(The earliest reference I can find to Canton Alley in The Seattle Star, The Seattle Times, or the Seattle Post-Intelligencer is an article in the February 12, 1911, issue of the Times.)
One major difference between Canton and Maynard Alleys is the house numbers, as mentioned in the excerpt from the summary and fiscal note to the ordinance above. House numbers on Maynard Alley S follow the standard pattern; the 500 block of Maynard Alley is the one south of S King Street, due west of the 500 block of 7th Avenue S, that of 8th Avenue S, etc. But house numbers on Canton Alley S follow the “European system” (also used in American cities like New York), so very low addresses such as 9 Canton Alley S exist — quite rare in Seattle — and were not changed by the ordinance.