The 1878 South Northumberland by-election was fought on 17 April 1878. The by-election was fought due to the succession to a peerage of the incumbent Conservative MP, Lord Eslington. It was won by the Conservative candidate Edward Ridley. [1]
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Conservative | Edward Ridley | 2,909 | 50.1 | N/A | |
| Liberal | Albert Grey | 2,903 | 49.9 | N/A | |
| Majority | 6 | 0.2 | N/A | ||
| Turnout | 5,812 | 78.4 | N/A | ||
| Registered electors | 7,415 | ||||
| Conservative hold | |||||