William Willoughby Miller (September 12, 1880[1] – 1959[2]) was a merchant and political figure in Saskatchewan.
He was born in Brockville, Ontario, the son of Willoughby Miller and Isabella Baker, and was educated in Greenbush.
Miller joined his brother in New York City, where he worked in a grocery and butcher business for three years.
Miller farmed in Leeds County for six years and then, in 1910, travelled west to Biggar, Saskatchewan, where he purchased a general store.
Miller served on the Biggar city council and the local school board.