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 born in Moncton, New Brunswick and educated in Moncton and Truro, Nova Scotia.
Sumner married Margaret T.
McEwan.
He was a hardware merchant and was also involved in production and export of lumber.
Sumner served six terms as mayor of Moncton.
He also served as Agent-General for New Brunswick.
He ran unsuccessfully for a seat in the House of Commons in 1908.
Two of his former homes in Moncton were designated Local Historic Places.