Ohio elected its members October 12, 1858, netting a 3-seat Republican gain.
| District | Incumbent | Party | First elected | Result | Candidates[1] | |||
|---|---|---|---|---|---|---|---|---|
| George H. Pendleton | Democratic | 1856 | Incumbent re-elected. | nowrap | ||||
| William S. Groesbeck | Democratic | 1856 | Incumbent lost re-election. New member elected. Republican gain. | nowrap | ||||
| Clement L. Vallandigham | Democratic | 1856 | Incumbent re-elected. | nowrap | ||||
| Matthias H. Nichols | Republican | 1852 | Incumbent lost re-election. New member elected. Democratic gain. | nowrap | ||||
| Richard Mott | Republican | 1854 | Incumbent retired. New member elected. Republican hold. | nowrap | ||||
| Joseph R. Cockerill | Democratic | 1856 | Incumbent retired. New member elected. Democratic hold. | nowrap | ||||
| Aaron Harlan | Republican | 1852 | Incumbent lost renomination. New member elected. Republican hold. | nowrap | ||||
| Benjamin Stanton | Republican | 1854 | Incumbent re-elected. | nowrap | ||||
| Lawrence W. Hall | Democratic | 1856 | Incumbent lost re-election. New member elected. Republican gain. | nowrap | ||||
| Joseph Miller | Democratic | 1856 | Incumbent lost re-election. New member elected. Republican gain. | nowrap | ||||
| Albert C. Thompson | Republican | 1854 | Incumbent retired. New member elected. Democratic gain. | nowrap | ||||
| Samuel S. Cox | Democratic | 1856 | Incumbent re-elected. | nowrap | ||||
| John Sherman | Republican | 1854 | Incumbent re-elected. | nowrap | ||||
| Philemon Bliss | Republican | 1854 | Incumbent retired. New member elected. Republican hold. Successor died May 31, 1859, leading to a special election. | nowrap | ||||
| Joseph Burns | Democratic | 1856 | Incumbent lost re-election. New member elected. Republican gain. | nowrap | ||||
| Cydnor B. Tompkins | Republican | 1856 | Incumbent re-elected. | nowrap | ||||
| William Lawrence | Democratic | 1856 | Incumbent retired. New member elected. Republican gain. | nowrap | ||||
| Benjamin F. Leiter | Republican | 1854 | Incumbent retired. New member elected. Republican hold. | nowrap | ||||
| Edward Wade | Republican | 1852 | Incumbent re-elected. | nowrap | ||||
| Joshua Reed Giddings | Republican | 1843 | Incumbent lost renomination. New member elected. Republican hold. | nowrap | ||||
| John Bingham | Republican | 1854 | Incumbent re-elected. | nowrap |