The 2023 election to Lisburn and Castlereagh City Council was held on 18 May 2023, alongside other local elections in Northern Ireland, two weeks after local elections in England. The Northern Ireland elections were delayed by 2 weeks to avoid overlapping with the coronation of King Charles III.

The election returned 40 members to the council via Single Transferable Vote.  This consisted of 14 Democratic Unionist Party members (who topped the polls in three districts: Castlereagh East, Downshire East and Lisburn South), 13 Alliance Party members (who topped the polls in two districts: Castlereagh South and Downshire West),  6 Ulster Unionist Party members, 4 Sinn Féin members (who topped the polls in two districts: Killultagh and Lisburn North), 2 Social Democratic and Labour Party members and 1 Independent member.

Election results 

|-
| colspan="2" style="background-color:#f2f2f2;text-align:center;margin-bottom:-1px;border:1px solid #aaa;padding:.2em .4em" | Total
| style="text-align:right;" | 40
|
| 
|
|
|
| style="text-align:right;" | 56,404
|<noinclude>

Note: "Votes" are the first preference votes.

Districts summary 

|- class="unsortable" align="centre"
!rowspan=2 align="left"|District Electoral Area (DEA)
! % 
!Cllrs
! %
!Cllrs
! %
!Cllrs
! %
!Cllrs
! %
!Cllrs
! %
!Cllrs
!rowspan=2|Totalcllrs
|- class="unsortable" align="center"
!colspan=2 bgcolor="" | DUP
!colspan=2 bgcolor="" | Alliance
!colspan=2 bgcolor="" | UUP
!colspan=2 bgcolor="" | Sinn Féin
!colspan=2 bgcolor=""| SDLP
!colspan=2 bgcolor="white"| Independents and others
|-
|align="left"|Castlereagh East
|bgcolor="#D46A4C"|50.92
|bgcolor="#D46A4C"|3 
|30.78
|2 
|9.03
|1 
|0.00
|0 
|0.00
|0 
|9.28
|0 
|6
|-
|align="left"|Castlereagh South
|15.05
|1 
|bgcolor="#F6CB2F"|32.36
|bgcolor="#F6CB2F"|3  1
|7.46
|0  1
|21.61
|2  1
|17.05
|1 
|6.92
|0  1
|7
|-
|align="left"|Downshire East
|bgcolor="#D46A4C"|41.34
|bgcolor="#D46A4C"|2 
|30.06
|2  1
|17.47
|1  1
|0.00
|0 
|4.51
|0 
|5.73
|0 
|5
|-
|align="left"|Downshire West
|bgcolor="#D46A4C"|40.19
|bgcolor="#D46A4C"|2 
|36.62
|2  1
|17.26
|1  1
|4.21
|0 
|0.00
|0 
|1.73
|0 
|5
|-
|align="left"|Killultagh
|bgcolor="#D46A4C"|33.49
|bgcolor="#D46A4C"|2 
|22.22
|1 
|15.66
|1 
|23.36
|1 
|4.34
|0 
|0.93
|0 
|5
|-
|align="left"|Lisburn North
|bgcolor="#D46A4C"|26.47
|bgcolor="#D46A4C"|1  1
|23.61
|1 
|13.65
|1  1
|14.67
|1  1
|11.07
|1 
|10.54
|1  1
|6
|-
|align="left"|Lisburn South
|bgcolor="#D46A4C"|38.20
|bgcolor="#D46A4C"|3 
|23.81
|2  1
|19.95
|1  1
|6.58
|0 
|6.30
|0 
|5.16
|0 
|6
|- class="unsortable" class="sortbottom" style="background:#C9C9C9"
|align="left"| Total
|34.02
|14  1
|28.48
|13  4
|13.97
|6  5
|10.98
|4  2
|6.69
|2 
|5.87
|1 
|40
|-
|}

District results

Castlereagh East 

2019: 3 x DUP, 2 x Alliance, 1 x UUP

2023: 3 x DUP, 2 x Alliance, 1 x UUP

2019–2023 Change: No change

Castlereagh South 

2019: 2 x Alliance, 1 x DUP, 1 x SDLP, 1 x Sinn Féin, 1 x UUP, 1 x Green

2023: 3 x Alliance, 2 x Sinn Féin, 1 x DUP, 1 x SDLP

2019–2023 Change: Alliance and Sinn Féin gain from Green and UUP

Downshire East 

2019: 2 x DUP, 2 x UUP, 1 x Alliance

2023: 2 x DUP, 2 x Alliance, 1 x UUP

2019–2023 Change: Alliance gain from UUP

Downshire West 

2019: 2 x DUP, 2 x UUP, 1 x Alliance

2023: 2 x DUP, 2 x Alliance, 1 x UUP

2019–2023 Change: Alliance gain from UUP

Killultagh 

2019: 2 x DUP, 1 x Alliance, 1 x UUP, 1 x Sinn Féin

2023: 2 x DUP, 1 x Sinn Féin, 1 x Alliance, 1 x UUP

2019–2023 Change: No change

Lisburn North 

2019: 2 x DUP, 2 x UUP, 1 x Alliance, 1 x SDLP

2023: 1 x DUP, 1 x Alliance, 1 x Sinn Féin, 1 x UUP, 1 x SDLP, 1 x Independent

2019–2023 Change: Sinn Féin and Independent gain from DUP and UUP

Lisburn South 

2019: 3 x DUP, 2 x UUP, 1 x Alliance

2023: 3 x DUP, 2 x Alliance, 1 x UUP

2019–2023 Change: Alliance gain from UUP

Notes

References 

2023 Northern Ireland local elections
21st century in County Antrim
21st century in County Down
Elections in County Antrim
Elections in County Down