William Donahue (August 12, 1834 – July 15, 1892) was a merchant and political figure in Quebec.
He represented Missisquoi in the House of Commons of Canada from 1874 to 1878 as a Liberal member.He was born in Frampton, Lower Canada, the son of Michael Donahue and Mary Murphy, Irish immigrants.
Donahue was a merchant in West Farnham and Montreal.
In 1882, he married Mary Ann Miller.
Donahue served as a member of the municipal council for Missisquoi County.
He was mayor of the village of Farnham from 1872 to 1874.