Authier (French pronunciation: [otje]) is a municipality in northwestern Quebec, Canada, in the Abitibi-Ouest Regional County Municipality. It had a population of 290 in the 2021 Canadian census.

The municipality was constituted on September 20, 1918, and is named after Hector Authier (1881–1971).

Historical census populations – Authier, Quebec

Year Pop. ±% 1976 461 —     1981 389 −15.6% 1986 381 −2.1% 1991 361 −5.2% 1996 324 −10.2%	Year Pop. ±% 2001 318 −1.9% 2006 247 −22.3% 2011 282 +14.2% 2016 268 −5.0% 2021 290 +8.2%
Population figures based on revised counts. Source: Statistics Canada

Private dwellings occupied by usual residents (2021): 129 (total dwellings: 134)

Mother tongue (2021):

• English as first language: 0%
• French as first language: 98.3%
• English and French as first language: 1.7%
• Other as first language: 0%

Municipal council (as of 2023):

• Mayor: Yvon Gagné
• Councillors: Nathalie Gaudette, Angèle Auger, Cindy Demers, Ghislain Desaulniers, Véronique Hince, François Deschênes

List of former mayors:

This list is incomplete; you can help by adding missing items. (July 2023)

• Rita Julien (...–2001)
• Pierre Lambert (2005–2013)
• Marcel Cloutier (2013–2022)
• Yvon Gagné (2022–present)