He graduated from Yale College in 1829 and commenced the study of law, but his health becoming impaired, he instead engaged in agricultural pursuits in Bloomfield.

He was elected a Free Soiler to the United States Senate in 1854 to fill a vacancy and served until the end of the term in 1855, not being a candidate for reelection.

Afterwards, Gillette became a lecturer on agriculture and temperance and was a trustee of the Connecticut State Normal School, also serving as its president for many years.

The Francis Gillette House in Bloomfield, Connecticut, his home in early years of his antislavery involvement, is listed on the U.S. National Register of Historic Places.

[1] This article incorporates public domain material from the Biographical Directory of the United States Congress