New Hampshire gained one seat after the 1810 census. Its elections were held August 31, 1812.
| District | Incumbent | This race | |||||
|---|---|---|---|---|---|---|---|
| Representative | Party | First elected | Results | Candidates | |||
| Josiah Bartlett Jr. | Democratic-Republican | 1810 | Incumbent retired. New member elected. Federalist gain. | √ Roger Vose (Federalist) 9.0% √ Daniel Webster (Federalist) 9.0% √ Bradbury Cilley (Federalist) 9.0% √ William Hale (Federalist) 9.0% √ Samuel Smith (Federalist) 9.0% √ Jeduthun Wilcox (Federalist) 8.9% David Morrill (Democratic-Republican) 7.7% John Parrott (Democratic-Republican) 7.7% Samuel Dinsmoor (Democratic-Republican) 7.7% John Adams Harper (Democratic-Republican) 7.7% Jesse Johnson (Democratic-Republican) 7.7% Josiah Butler (Democratic-Republican) 7.6% | |||
| Samuel Dinsmoor | Democratic-Republican | 1810 | Incumbent lost re-election. New member elected. Federalist gain. | ||||
| Obed Hall | Democratic-Republican | 1811 | Incumbent retired. New member elected. Federalist gain. | ||||
| John Adams Harper | Democratic-Republican | 1811 | Incumbent lost re-election. New member elected. Federalist gain. | ||||
| George Sullivan | Federalist | 1811 | Incumbent retired. New member elected. Federalist hold. | ||||
| None (Seat created) | New seat. New member elected. Federalist gain. | ||||||