| Henry Ker Seymer | |
| Office: | Member of Parliament for Dorset |
| Term Start: | 19 February 1846 |
| Term End: | 28 May 1864 |
| Alongside: | Henry Portman (1857–1864) Henry Sturt (1856–1864) John Floyer (1846–1857) George Bankes (1846–1856) |
| Predecessor: | Anthony Ashley-Cooper Henry Sturt George Bankes |
| Birth Date: | 1807 |
| Nationality: | British |
| Party: | Conservative |
Henry Ker Seymer (1807 – 28 May 1864)[1] was a British Conservative politician.
Seymer was first elected Conservative MP for Dorset, alongside John Floyer, at a by-election in 1846—caused by the resignations of Anthony Ashley-Cooper and Henry Sturt—and held the seat until his death in 1864.[2]