A special election was held in New York's 12th congressional district on April 26–28, 1808 to fill a vacancy left by the resignation, on February 5, 1808, of David Thomas (DR), who had been appointed New York State Treasurer. This election was held at the same time as the 1808 Congressional elections. As New York had redistricted in the meantime, Thomas' former district no longer existed as a separate district, but was now a part of the 6th district. The special election was held in the territory of the old 12th district