2012 Cardiff South and Penarth by-election
| 
 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| The Cardiff South and Penarth Parliamentary seat in the House of Commons | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Turnout | 25.7% | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| 
 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 
 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
Following the resignation of the sitting MP Alun Michael on 22 October 2012, a by-election for the Cardiff South and Penarth Westminster constituency was held on 15 November 2012.
Stephen Doughty of the Labour Party won the election with 47.3% of the vote.
The by-election was held on the same day as the Manchester Central and Corby by-elections, and the inaugural Police and Crime Commissioner elections.