The majority requirement was met in all 17 districts in the 1804 elections.
| District | Incumbent | Party | First elected | Result | Candidates | ||||
|---|---|---|---|---|---|---|---|---|---|
| William Eustis | Democratic-Republican | 1801 | Incumbent lost re-election. New member elected. Federalist gain. | nowrap | √ Josiah Quincy (Federalist) 51.0% William Eustis (Democratic-Republican) 49.0% | ||||
| Jacob Crowninshield | Democratic-Republican | 1803 | Incumbent re-elected. | nowrap | √ Jacob Crowninshield (Democratic-Republican) 58.7% Nathan Read (Federalist) 41.2% | ||||
| Manasseh Cutler | Federalist | 1801 | Incumbent retired. New member elected. Federalist hold. | nowrap | √ Jeremiah Nelson (Federalist) 56.8% Thomas Kitteridge (Democratic-Republican) 43.2% | ||||
| Joseph Bradley Varnum | Democratic-Republican | 1794 | Incumbent re-elected. | nowrap | √ Joseph Bradley Varnum (Democratic-Republican) 71.5% Timothy Bigelow (Federalist) 28.0% | ||||
| Thomas Dwight | Federalist | 1803 | Incumbent retired. New member elected. Federalist hold. | nowrap | √ William Ely (Federalist) 62.9% Samuel Fowler (Democratic-Republican) 36.7% | ||||
| Samuel Taggart | Federalist | 1803 | Incumbent re-elected. | nowrap | √ Samuel Taggart (Federalist) 69.3% Solomon Snead (Democratic-Republican) 30.5% | ||||
| Nahum Mitchell | Federalist | 1803 | Incumbent lost re-election. New member elected. Democratic-Republican gain. | nowrap | √ Joseph Barker (Democratic-Republican) 60.4% Nahum Mitchell (Federalist) 38.3% Others 1.3% | ||||
| Lemuel Williams | Federalist | 1798 | Incumbent lost re-election. New member elected. Democratic-Republican gain. | nowrap | √ Isaiah L. Green (Democratic-Republican) 60.1% Lemuel Williams (Federalist) 39.4% | ||||
| Phanuel Bishop | Democratic-Republican | 1798 | Incumbent re-elected. | nowrap | √ Phanuel Bishop (Democratic-Republican) 62.2% Nicholas Tillinghast (Federalist) 30.8% Josiah Deane (Democratic-Republican) 3.4% John Bowers (Federalist) 3.4% | ||||
| Seth Hastings | Federalist | 1801 (Special) | Incumbent re-elected. | nowrap | √ Seth Hastings (Federalist) 51.2% Edward Bangs (Democratic-Republican) 48.8% | ||||
| William Stedman | Federalist | 1803 | Incumbent re-elected. | nowrap | √ William Stedman (Federalist) 60.8% John Whiting (Democratic-Republican) 39.0% | ||||
| Simon Larned | Democratic-Republican | 1804 (special) | Incumbent retired. New member elected. Democratic-Republican hold. | nowrap | √ Barnabas Bidwell (Democratic-Republican) 59.7% Daniel Dewey (Federalist) 40.3% | ||||
| Ebenezer Seaver | Democratic-Republican | 1803 | Incumbent re-elected. | nowrap | √ Ebenezer Seaver (Democratic-Republican) 64.6% Thomas B. Adams (Federalist) 35.0% | ||||
| Richard Cutts | Democratic-Republican | 1801 | Incumbent re-elected. | nowrap | √ Richard Cutts (Democratic-Republican) 51.9% Joseph Leland (Federalist) 31.4% Daniel Cleaves 16.7% | ||||
| Peleg Wadsworth | Federalist | 1792 | Incumbent re-elected. | nowrap | √ Peleg Wadsworth (Federalist) 63.8% William Widgery (Democratic-Republican) 19.1% Isaac Parsons (Democratic-Republican) 17.1% | ||||
| Samuel Thatcher | Federalist | 1802 (Special) | Incumbent retired. New member elected. Democratic-Republican gain. | nowrap | √ Orchard Cook (Democratic-Republican) 54.6% Samuel Thatcher 45.4% | ||||
| Phineas Bruce | Federalist | 1803 | Incumbent retired. New member elected. Democratic-Republican gain. | nowrap | √ John Chandler (Democratic-Republican) 64.5% Benjamin Whitwell (Federalist) 35.5% | ||||