A special election was held in Connecticut's at-large district in 1817[a] to fill two vacancies in the 15th Congress, both of which had occurred before the start of that Congress.
The vacancies were left by the death of members-elect Sylvanus Backus (F) on February 15, 1817, and Charles Dennison (F) who declined the seat.
As there were two vacancies in an at-large district, the top two candidates were elected to represent Connecticut.
Huntington and Terry took their seats with the rest of the 15th Congress.