1st October 2015 (8)
7th October 2015 (2)
8th October 2015 (6)
15th October 2015 (3)
22nd October 2015 (6)
29th October 2015 (6)
Collated by MiddleEnglander
There were 31 by-elections during October 2015 with 8(26%) changing hands, The results can be summarised by:
| Party | Candidates | Defended | Retained | Gained | Lost | Won | retention rate |
| Conservative | 30 | 10 | 7 | 3 | 3 | 10 | 70% |
| Labour | 26 | 8 | 7 | 1 | 1 | 8 | 88% |
| Liberal Democrat | 21 | 3 | 1 | 2 | 2 | 3 | 33% |
| SNP | 8 | 6 | 5 | 1 | 1 | 6 | 83% |
| Plaid Cymru | 1 | ||||||
| UKIP | 17 | 1 | 1 | 1 | 100% | ||
| Green | 19 | 1 | 1 | 1 | 100% | ||
| Independent | 5 | 2 | 1 | 1 | 1 | 50% | |
| All People | 1 | ||||||
| Baker Street: No 2 Way | 1 | ||||||
| TUSC | 3 | ||||||
| No Description | 2 | 1 | 1 | ||||
| Total | 134 | 31 | 23 | 8 | 8 | 31 | 74% |
The Conservatives gained 1 seat from Labour and 2 seats from the Liberal Democrats:
- Brentwood, Shenstone from a Liberal Democrat on a 2.7% swing Conservative to Liberal Democrat since May
during this century the Liberal Democrats has won this ward only in 2012, December 2012 by-election and 2014
- Bury, Tottington from Labour on a ¾% swing Labour to Conservative since May.
during this century Labour has won this ward only in 2012 with the former Councillor now forced to resign over child porn.
- Woking, Goldstone West from a Liberal Democrat on a swing Liberal Democrat to Conservative of 3.3% since 2014
Liberal Democrats had won this seat in every election this century although they did retain Goldstone East which a Conservative won in 2011, 2014 and 2015
The Conservatives lost 1 seat each to Labour, a Liberal Democrat and SNP
- Aberdeen, Midstocket / Rosemount to SNP on a 3.9% swing SNP to Conservatives since 2012 in a ward then won with less than 14% first preference share
- Cherwell, Banbury Grimbury & Castle to Labour on a 2.6% swing Conservative to Labour since May
Labour won this seat in 2002, 2011, 2014 and 2015 with the Conservatives winning in the other years
- Wealden, Hellingly where a Liberal Democrat, elected in 2003, 2007 and 2011, regained the seat on 32% swing unexpectedly lost in May
one of the two Conservatives elected in May resigned and fought the by-election as an Independent coming bottom of three with 12.3% share
A Liberal Democrat gained Highland, Aird and Loch Ness from SNP where 2 Independents, 1 SNP and 1 Liberal Democrat were elected in 2012
No Description gained Western Isles, West Side & Ness from an Independent
Elsewhere Conservatives easily retained Colchester: Dedham & Langham (69% majority), South Oxfordshire: Sonning Common (45%) and Westminster: Bryanston & Dorset Square (31%), comfortably retained Peterborough: West (17%) and Hampshire: Chandler's Ford (14%) but both South Oxfordshire: Stanford & The Wittenhams (6%) and Cheshire East: Congleton East (8%) became Conservative / Liberal Democrat marginals.
Labour had solid wins in Oxford: Northfield Brook (69% majority), Southwark: South Camberwell ( 37%) and Barrow-in-Furness: Risedale (29%) whilst Chorley: Euxton North saw a comfortable win (21%) in a seat the Conservatives won in 2008 and 2010. Bolsover: Bolsover South (19%), Cumbria: Howgate (14%) and Cardiff: Riverside were somewhat closer than possibly expected.
Two close results were a Liberal Democrat hold in Woking: Goldstone East ( 2%) and a UKIP hold in Cambridgeshire: Chatteris where the majority over a Conservative increased from 5 in 2013 to 10 (0.7% in the by-election.
