55th Parliament of the United Kingdom By-elections
- 13 January 2011 - Oldham East and Saddleworth
- 3 March 2011 - Barnsley Central
- 5 May 2011 - Leicester South
- 9 June 2011 - Belfast West
- 30 June 2011 - Inverclyde
- 15 December 2011 - Feltham and Heston
- 29 March 2012 - Bradford West
- 15 November 2012 - Cardiff South and Penarth
- 15 November 2012 - Corby
- 15 November 2012 - Manchester Central
- 29 November 2012 - Croydon North
- 29 November 2012 - Middlesbrough
- 29 November 2012 - Rotherham
- 28 February 2013 - Eastleigh
- 7 March 2013 - Mid Ulster
- 2 May 2013 - South Shields
- 13 February 2014 - Wythenshawe and Sale East
- 5 June 2014 - Newark
- 9 October 2014 - Clacton
- 9 October 2014 - Heywood and Middleton
- 20 November 2014 - Rochester and Strood
Read the House of Commons Library briefing on by-elections in the 55th Parliament.