Olivier-Napoléon Drouin (1862–1934) was a Canadian politician, the mayor of Quebec City from 1910 to 1916.

After representing Quebec City's Saint-Roch ward as alderman since 1896, Drouin won the 1910 mayoralty contest with a 1328 vote margin over his opponent, federal politician Philippe-Auguste Choquette.

Drouin won re-election to successive terms in office in 1912 and 1914.

During his terms as mayor, he oversaw the annexation of the communities of Belvedère, Limoilou and Saint-Malo to Quebec City.

After leaving the mayor's posting in 1916, Drouin chaired the Commission des chemins du Québec (Commission of routes of Quebec) between 1917 and 1922.