Langdon was born to Ebenezer and Katherine (Green) Langdon in Farmington in the Connecticut Colony. Pursuing classical studies, he graduated from Yale College in 1787, where he was a member of Brothers in Unity.^[1] He then studied at the Litchfield Law School and with Judge Sylvester Gilbert, of Hebron, Connecticut, and was admitted to the bar. He began the practice of law in Castleton, Vermont.

Langdon became an active Federalist. He practiced law in Windsor, but later returned to Castleton. He served as the Rutland County Register of Probate from 1792 to 1794, in 1796, and again in 1813. He was Judge of Probate in 1798 and 1799. In 1808 he served on the state Executive Council.^[2] He received an honorary degree at Middlebury Collegein Vermont in 1803 and was a trustee from 1811 until his death. He was a member of the Vermont House of Representatives in 1813, 1814, 1817, 1819, 1820, and 1822.^[3]

Langdon was elected as a Federalist to the Fourteenth Congress, serving from March 4, 1815, until March 3, 1817.^[4] He was not a candidate for renomination to the Fifteenth Congress. He was again elected to the Executive Council and served from 1823 until his death.^[5]

He married Lucy Nona Lathrop Langdon on April 7, 1789. They had one son, Benjamin Franklin Langdon,^[6] and one daughter, Lucy Green Langdon Williams,^[7] who married Governor Charles K. Williams.^[8]

Langdon died in Castleton on July 23, 1830. He is interred in Castleton's Congregational Cemetery.^[9] He was also an officer of the Vermont Bible Society.

• United States Congress. "Chauncey Langdon (id: L000066)". Biographical Directory of the United States Congress.
• Litchfield Historical Society
• Chauncey Langdon
• Chauncey Langdon at Find a Grave
• The Political Graveyard