The 1963 Deptford by-election was held on 4 July 1963 [1] following the death of the incumbent Labour MP Sir Leslie Plummer on 15 April. The seat was comfortably retained by the future Cabinet Member John Silkin.
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Labour | John Silkin | 12,209 | 58.25 | −3.70 | |
| Liberal | David John Howard Penwarden | 4,726 | 22.55 | N/A | |
| Conservative | John D Brimacombe | 4,023 | 19.20 | −18.85 | |
| Majority | 7,483 | 35.70 | +11.80 | ||
| Turnout | 20,958 | ||||
| Labour hold | Swing | ||||