| Election Name: | 1993 Christchurch by-election |
| Type: | parliamentary |
| Country: | United Kingdom |
| Seats For Election: | Constituency of Christchurch |
| Ongoing: | no |
| Previous Election: | 1992 United Kingdom general election |
| Previous Year: | 1992 |
| Next Election: | 1997 United Kingdom general election |
| Next Year: | 1997 |
| Election Date: | 29 July 1993 |
| Turnout: | 74.2% |
| Candidate1: | Diana Maddock |
| Party1: | Liberal Democrats (UK) |
| Popular Vote1: | 33,164 |
| Percentage1: | 62.2% |
| Swing1: | 38.6% |
| Candidate2: | Robert Hayward |
| Party2: | Conservative Party (UK) |
| Popular Vote2: | 16,737 |
| Percentage2: | 31.4% |
| Swing2: | 32.2% |
| MP | |
| Before Election: | Robert Adley |
| Before Party: | Conservative Party (UK) |
| After Election: | Diana Maddock |
| After Party: | Liberal Democrats (UK) |
A by-election was held in the British House of Commons constituency of Christchurch on 29 July 1993 following the death of sitting Conservative MP Robert Adley.
The result was a gain for the Liberal Democrats, notable for the swing necessary to take such a strong Conservative seat, gaining more than 60% of the votes cast and winning practically twice as many votes as the Conservatives., the swing of 35.4% remains the sixth-largest by-election swing in British political history (the Bermondsey by-election in 1983 having the largest). It was also the largest swing (35%) against any British government since 1918.[1]
At the time, it was not necessary for candidates in British elections to register party names or ballot paper descriptions. Details on candidates at this election are taken from the official count[2] and David Boothroyd's election results site.[3]