Franklin Thomas Backus (May 6, 1813 – May 14, 1870) was an American lawyer and politician.

While he was very young the family moved to Lansing, New York He prepared himself for college while assistant teacher in an academy in Delaware kept by an older brother, and entered Yale College as a Junior in 1834.

On leaving college in 1836, he established a classical school in Cleveland, Ohio, and at the same time began the study of law.

In 1861, he was a member of the Peace Convention which met in Washington, with the hope of averting the American Civil War.

His services were especially sought for by railroad corporations, and it is to the excessive and exhausting labor thus brought upon him that his death, from a disease of the heart, is to be attributed.