Frederick Smyth (March 9, 1819 – April 22, 1899) was an American banker, railroad executive, and politician from Manchester, New Hampshire.

He continued to be a merchant until 1849, when he sold his share of the business following his election to the post of Manchester city clerk at the age of 30.

In 1857 and 1858, he was a member of the New Hampshire General Court, representing Manchester's ward 3.

He was active in the New Hampshire Agriculture Society, serving as treasurer for 10 years.

He served as one of the commissioners on the part of the General Government of New Hampshire at the International Exhibition of 1862, in London.

Smyth's terms as governor were consumed by efforts to straighten out the state's wartime finances, which were in substantial disarray because of Civil War expenditures.

On July 7, 1866, during his second term as governor, Smyth signed a bill providing for the incorporation of the New Hampshire College of Agriculture and the Mechanic Arts.

Smyth served as one of the board of managers of the National Homes for Disabled Soldiers.

He was a delegate-at-large to the 1872 Republican national convention, and President Hayes appointed him honorary commissioner to the 1878 International Exposition at Paris.

He was a trustee of the New England Conservatory of Music in Boston, and served as president of the New Hampshire Orphans' Home at Franklin.

The trust provides scholarships to music students in the greater Manchester area.