William Somerville Edmiston (November 10, 1857 – July 24, 1903) was an architect and politician in present-day Alberta, Canada.

Originally a native of Scotland, Edmiston came to Canada to settle in Clover Bar, Northwest Territories in the early 1880s.

The firm designed many notable buildings for the town, including the first post office,[10] the city's first brick school (for the Edmonton Public School District), the All Saints' Anglican Cathedral, a home for Herbert Charles Wilson, the McDougall & Secord retail store, and a fire hall.

This firm was responsible for constructing, amongst many, a hospital building, a new Presbyterian church and making alterations to the Robertson Hall Theatre.

[12] In 1900, an article was published in the Edmonton Bulletin, praising the firm Edmiston & Johnson, specifically for their "skill and artistic tastes", stating that they had "built for themselves a reputation that is second to none in their line".

[15] In 1895, Edmiston was nominated for and subsequently elected to Edmonton Town Council, finishing first in the aldermanic race in a field of nine candidates, with 175 votes.

[7] He also introduced bylaws that permitted a new flour mill to operate with reduced taxation rates,[23] authorized the widening of Queen Street,[24] and provided for the purchase of additional property for the expansion of the town.

[25][26] In May 1900, Edmiston, along with notables Alex Taylor, John Alexander McDougall, James McDonald, William Johnston Walker, Robert Manson, Thomas Bellamy, Herman McInnes, and Hedley C. Taylor, were named to The Edmonton Public Hospital corporate governing board, on the advice of the Legislative Assembly of the North-West Territories.

[1] His obituary lauded that he was a well-respected citizen who had "always taken a prominent part in all matters pertaining to the welfare of [Edmonton].

[35] The architectural firm of Edmiston & Johnson lasted up until the 1960s, changing partners multiple times, and ultimately folding in 1964 under the name Howard and Robert Bouey Architects.