7, 1849 |- | | | George Perkins Marsh (W) | style="font-size:80%" | Resigned some time in 1849 | | James Meacham (W) | Seated December 3, 1849 |- | | | Rodolphus Dickinson (D) | style="font-size:80%" | Died March 20, 1849 | | Amos E. Wood (D) | Seated December 3, 1849 |- | | | Alexander Newman (D) | style="font-size:80%" | Died September 8, 1849 | | Thomas Haymond (W) | Seated November 8, 1849 |- | | | Thomas B. King (W) | style="font-size:80%" | Resigned March 3, 1850 | | Joseph W. Jackson (D) | Seated March 4, 1850 |- | | | Daniel P. King (W) | style="font-size:80%" | Died July 25, 1850 | Vacant | Not filled this term |- | | | William Thompson (D) | style="font-size:80%" | Seat declared vacant June 29, 1850, after contested election. House ruled neither candidate entitled to seat and forced special election | | Daniel F. Miller (W) | Seated December 20, 1850 |- | | | Robert C. Winthrop (W) | style="font-size:80%" | Resigned July 30, 1850, after being appointed to the US Senate | | Samuel A. Eliot (W) | Seated August 22, 1850 |- | | | Charles M. Conrad (W) | style="font-size:80%" | Resigned August 17, 1850, after being appointed United States Secretary of War | | Henry A. Bullard (W) | Seated December 5, 1850 |- | | | James Wilson (W) | style="font-size:80%" | Resigned September 9, 1850 | | George W. Morrison (D) | Seated October 8, 1850 |- | | colspan=2 style="font-size:80%" | California admitted into the Union September 9, 1850, and seat remained vacant until September 11, 1850 | | Edward Gilbert (D) | Seated September 11, 1850 |- | | colspan=2 style="font-size:80%" | California admitted into the Union September 9, 1850, and seat remained vacant until September 11, 1850 | | George W. Wright (I) | Seated September 11, 1850 |- | | | Henry Nes (W) | style="font-size:80%" | Died September 10, 1850 | | Joel B. Danner (D) | Seated December 2, 1850 |- | | | Chester P. Butler (W) | style="font-size:80%" | Died October 5, 1850 | | John Brisbin (D) | Seated November 13, 1850 |- | | | John H. Harmanson (D) | style="font-size:80%" | Died October 24, 1850 | | Alexander G. Penn (D) | Seated December 30, 1850 |-