Frederick William Sumner (April 12, 1855 – November 20, 1919) was a merchant and political figure in New Brunswick, Canada.
He represented Westmorland County in the Legislative Assembly of New Brunswick from 1895 to 1899 as a Conservative member.
He was a hardware merchant and was also involved in production and export of lumber.
Sumner served six terms as mayor of Moncton.
Two of his former homes in Moncton were designated Local Historic Places.