(1802-1838), nephew of Bradbury Cilley (U.S. Representative from New Hampshire 1813-1817) and brother of Joseph Cilley U.S. Senator from New Hampshire), was a U.S. Representative who was born in Nottingham, Rockingham County, New Hampshire on July 2, 1802. He attended Atkinson Academy in New Hampshire, was graduated from New Hampton Academy and later, in 1825, from Bowdoin College.
Cilley studied law, was admitted to the bar in 1828, and began practice in Thomaston. Editor of the Thomaston Register 1829-1831, he became a member of the Maine House of Representatives (1831-1836) and served as Speaker of the House in 1835 and 1836.
Elected as a Democrat to the Twenty-fifth Congress, he served from March 4, 1837 until February 24, 1838, when he was killed in a duel on the Marlboro Pike, near Washington, D.C., by William J. Graves, a Representative from Kentucky. He is interred in Cilley Cemetery in Thomaston.