# Arolygon barn ar annibyniaeth i Gymru

Gorymdaith dros annibyniaeth Merthyr, Medi 2019Dyma restr o arolygon barn sydd yn ymwneud â Annibyniaeth i Gymru.

## Arolygon Ie/Na dros annibyniaeth

| Dyddiad
 | Trefnwr
 | Maint sampl
 | A ddylai Cymru fod yn wlad annibynnol?
 | Eithrio ddim yn gwybod
 | Arwain
*(Newid ers arolwg diwethaf y trefnwr)* |
| --- | --- | --- | --- | --- | --- |
| Ie
 | Na
 | Di-benderfyniad |
| 7 Mau 2026
 | *Etholiad Senedd Cymru, 2026, lle ennillodd Plaid Cymru y nifer fwyaf o seddi* |
| 5-12 Ionawr 2026
 | YouGov
 | 1,220
 | 26%
 | 54%
 | 12%
 | 33% i 67%
 | 28% *(-9%)* |
| 24-27 Mawrth 2025
 | Redfield & Wilton Strategies
 | 1,000
 | 35%
 | 50%
 | 14%
 | 41% i 59%
 | 15% *(-9%)* |
| 18 Hydref - 4 Tachwedd 2024
 | Survation
 | 1,782
 | 30%
 | 51%
 | 19%
 | 37% i 63%
 | 21%
 |
| 2-8 Medi 2024
 | YouGov
 | 1,207
 | 24%
 | 61%
 | 15%
 | 28% i 72%
 | 37%
 |
| 3-7 Mehefin 2024
 | Redfield & Wilton Strategies Archifwyd 2024-06-08 yn y Peiriant Wayback
 | 960
 | 33%
 | 57%
 | 10%
 | 37% i 63%
 | 24%
 |
| 30 Mai-03 Mehefin 2024
 | YouGov
 | 1066
 | 24%
 | 53%
 | 14%
 | 31% i 69%
 | 29%
 |
| 18-19 Mai 2024
 | Redfield & Wilton Strategies Archifwyd 2024-05-22 yn y Peiriant Wayback
 | 900
 | 29%
 | 59%
 | 12%
 | 33% i 67%
 | 30%
 |
| 23-24 Mawrth 2024
 | Redfield & Wilton Strategies Archifwyd 2024-03-28 yn y Peiriant Wayback
 | 878
 | 30%
 | 58%
 | 11%
 | 34% i 66%
 | 32%
 |
| 18 Chwefror 2024
 | Redfield & Wilton Strategies Archifwyd 2024-02-21 yn y Peiriant Wayback
 | 874
 | 27%
 | 61%
 | 12%
 | 31% i 69%
 | 34%
 |
| 24-26 Ionawr 2024
 | Redfield & Wilton Strategies Archifwyd 2024-07-15 yn y Peiriant Wayback
 | 1,100
 | 30%
 | 59%
 | 11%
 | 34% i 66%
 | 29%
 |
| 10-11 Rhagfyr 2023
 | Redfield & Wilton Strategies Archifwyd 2023-12-13 yn y Peiriant Wayback
 | 1,086
 | 34%
 | 58%
 | 9%
 | 37% i 63%
 | 24%
 |
| 12-13 Tachwedd 2023
 | Redfield & Wilton Strategies Archifwyd 2023-11-15 yn y Peiriant Wayback
 | 1,100
 | 33%
 | 56%
 | 12%
 | 37% i 63%
 | 23%
 |
| 1-6 Medi 2023
 | YouGov
 |  | 22%
 | 56%
 | 13%
 | 28% i 72%
 | 34%
 |
| 13-14 Awst 2023
 | Redfield & Wilton Strategies
 | 1,068
 | 33%
 | 53%
 | 14%
 | 38% i 62%
 | 20%
 |
| 14–16 Gorffennaf 2023
 | Redfield & Wilton Strategies
 | 1,050
 | 32%
 | 58%
 | 10%
 | 36% i 64%
 | 26%
 |
| 17–18 Mehefin 2023
 | Redfield & Wilton Strategies
 | 1,000
 | 30%
 | 57%
 | 13%
 | 34% i 66%
 | 27%
 |
| 12–17 Mai 2023
 | YouGov/Barn Cymru
 | 1,064
 | 20%
 | 54%
 | 15%
 | 27% i 73%
 | 34%
 |
| 14–15 Mai 2023
 | Redfield and Wilton Strategies
 | 1,058
 | 32%
 | 58%
 | 11%
 | 36% i 64%
 | 26%
 |
| 15–17 Ebrill 2023
 | Redfield and Wilton Strategies
 | 1,251
 | 29%
 | 60%
 | 11%
 | 33% i 67%
 | 31%
 |
| 17–23 Chwefror 2023
 | YouGov / WalesOnline
 | 1,083
 | 18%
 | 55%
 | 16%
 | 25% i 75%
 | 37%
 |
| 25 Tachwedd – 1 Rhagfyr 2022
 | YouGov / Barn Cymru
 | 1,042
 | 22%
 | 55%
 | 14%
 | 29% i 71%
 | 33%
 |
| 21-25 Tachwedd 2022
 | YouGov / YesCymru
 | 1,033
 | 23%
 | 54%
 | 13%
 |  | 31%
 |
| 20–22 Medi 2022
 | YouGov / Barn Cymru
 | 1,014
 | 24%
 | 52%
 | 14%
 |  | 28%
 |
| 16–19 Awst 2022
 | YouGov / The Sunday Times
 | 1,025
 | 25%
 | 53%
 | 12%
 |  | 28%
 |
| 12–16 Mehefin 2022
 | YouGov / ITV Wales
 | 1,020
 | 25%
 | 50%
 | 25%
 |  | 25%
 |
| 25 Chwefror – 1 Mawrth 2022
 | YouGov/ Barn Cymru
 | 1,086
 | 21%
 | 53%
 | 26%
 |  | 32%
 |
| 5 Mai 2021
 | Savanta ComRes Archifwyd 2022-02-16 yn y Peiriant Wayback
 | 1,002
 | 30%
 | 55%
 | 15%
 |  | 25%
 |
| 2-4 Mai 2021
 | YouGov / Welsh Barometer
 | 1,071
 | 21%
 | 55%
 | 14%
 |  | 34%
 |
| 29 Ebrill – 4 Mai 2021
 | Savanta ComRes Archifwyd 2022-02-16 yn y Peiriant Wayback
 | 1,002
 | 27%
 | 58%
 | 14%
 |  | 31%
 |
| 23–28 Ebrill 2021
 | Savanta ComRes Archifwyd 2021-12-04 yn y Peiriant Wayback
 | 1,002
 | 42%
 | 49%
 | 8%
 |  | 7%
 |
| 18–21 Ebrill 2021
 | YouGov
 | 1,142
 | 22%
 | 54%
 | 24%
 |  | 32%
 |
| 9–19 Ebrill 2021
 | Opinium / Sky News
 | 2,005
 | 28%
 | 52%
 | 19%
 |  | 24%
 |
| 16–19 Mawrth 2021
 | Welsh Barometer Survey / YouGov
 | 1,174
 | 22%
 | 55%
 | 23%
 |  | 33%
 |
| 18–22 Chwefror 2021
 | Savanta ComRes / ITV News
 | 1,003
 | 35%
 | 55%
 | 10%
 |  | 20%
 |
| 19–22 Chwefror 2021
 | WalesOnline / YouGov
 | 1,059
 | 25%
 | 50%
 | 14%
 |  | 25%
 |
| 18–21 Ionawr 2021
 | The Sunday Times / YouGov
 | 1,059
 | 23%
 | 52%
 | 25%
 |  | 29%
 |
| 11–14 Ionawr 2021
 | Welsh Barometer Survey / YouGov
 | 1,018
 | 22%
 | 53%
 | 25%
 | 29% i 71%
 | 31%
 |
| 26–29 Hydref 2020
 | Welsh Barometer Survey / YouGov
 | 1,013
 | 23%
 | 53%
 | 25%
 | 30% i 70%
 | 30%
 |
| 24–27 Awst 2020
 | YesCymru / YouGov
 | 1,044
 | 25%
 | 52%
 | 23%
 | 32% i 68%
 | 27%
 |
| 29 Gorffennaf – 7 Awst 2020
 | YesCymru / YouGov
 | 1,044
 | 26%
 | 55%
 | 19%
 | 32% i 68%
 | 29%
 |
| 29 Mai – 1 Mehefin 2020
 | ITV Wales / YouGov / Cardiff Uni
 | 1,021
 | 25%
 | 54%
 | 21%
 | 32% i 68%
 | 29%
 |
| 20–26 Ionawr 2020
 | Welsh Barometer Survey / YouGov
 | 1,037
 | 21%
 | 57%
 | 22%
 | 27% i 73%
 | 36%
 |
| 6–9 Rhagfyr 2019
 | Welsh Barometer Survey / YouGov
 | 1,020
 | 17%
 | 60%
 | 23%
 | 22% i 78%
 | 43%
 |
| 22–25 Tachwedd 2019
 | Welsh Barometer Survey / YouGov
 | 1,116
 | 20%
 | 57%
 | 22%
 | 26% i 74%
 | 37%
 |
| 31 Hydref – 4 Tachwedd 2019
 | Welsh Barometer Survey / YouGov
 | 1,032
 | 22%
 | 57%
 | 21%
 | 28% i 72%
 | 35%
 |
| 10–14 Hydref 2019
 | Welsh Barometer Survey / YouGov
 | 1,032
 | 21%
 | 57%
 | 23%
 | 27% i 73%
 | 36%
 |
| 6–10 Medi 2019
 | Plaid Cymru / YouGov
 | 1,039
 | 24%
 | 52%
 | 23%
 | 32% i 68%
 | 28%
 |
| 7–14 Rhagfyr 2018
 | Sky News Data: Wales
 | 1,014
 | 17%
 | 67%
 | 16%
 | 20% i 80%
 | 50%
 |
| 30 Mai – 6 Mehefin 2018
 | YouGov
 | 2,016
 | 19%
 | 65%
 | 16%
 | 23% i 77%
 | 46%
 |
| Gorffennaf 2016
 | ITV Wales / YouGov Archifwyd 14 Awst 2020 yn y Peiriant Wayback
 | 1,010
 | 15%
 | 65%
 | 20%
 | 19% i 81%
 | 50%
 |
| 8–11 Medi 2014
 | ITV Wales / YouGov / Cardiff University
 | >1,000
 | 17%
 | 70%
 | 13%
 | 20% i 80%
 | 53%
 |
| Ebrill 2014
 | YouGov
 | 1,000
 | 12%
 | 74%
 | 14%
 | 14% i 86%
 | 62%
 |
| 5-8 Ionawr 2007
 | Opinion Research Business
 | 527
 | 19%
 | 69%
 | 13%
 | 22% i 78%
 | 50%
 |

## Cwestiynau â chyd-destun (ansafonol)

| Dyddiad
 | Trefnwr
 | Maint sampl
 | A ddylai Cymru fod yn wlad annibynnol?
 | Eithrio ddim yn gwybod
 | Arwain
 | Nodiadau
 |
| --- | --- | --- | --- | --- | --- | --- |
| Ie
 | Na
 | Di-benderfyniad
 |
| 24-27 Mawrth 2025
 | Redfield and Wilton
 | 1,000
 | i'w gadarnhau
 | i'w gadarnhau
 | i'w gadarnhau
 | 51% i 49%
 | i'w gadarnhau
 | Os fyddai Cymru annibynnol yn aeold o'r **Undeb Ewropeaidd** |
| 6–10 Medi 2019
 | Plaid Cymru / YouGov
 | 1,039
 | 33%
 | 48%
 | 20%
 | 41% i 59%
 | 15%
 |  Os fyddai Cymru annibynnol yn aeold o'r **Undeb Ewropeaidd** |
| Gorffennaf 2016
 | ITV Wales / YouGov Archifwyd 2020-08-14 yn y Peiriant Wayback
 | 1,010
 | 28%
 | 53%
 | 20%
 | 35% i 65%
 | 25%
 |  Os fyddai Cymru annibynnol yn aeold o'r **Undeb Ewropeaidd** |
| Gorffennaf 2016
 | ITV Wales / YouGov Archifwyd 2019-08-06 yn y Peiriant Wayback
 | 1,010
 | 19%
 | 61%
 | 21%
 | 24% i 76%
 | 42%
 | Os fyddai'r **Alban** yn annibynnol
 |
| Mawrth 2013
 | ITV Wales / YouGov
 | Unknown
 | 10%
 | 62%
 | 28%
 | 14% i 86%
 | 52%
 | Os fyddai'r **Alban** yn annibynnol
 |

## Oedran

|  |
| --- |
| Mae'r erthygl hon yn rhan o'r gyfres:
**Gwleidyddiaeth Cymru** |
|

---

 |
| **Llywodraeth Cymru Prif Weinidog: Rhun ap Iorwerth
* Dirprwy Brif Weinidog: Sioned Williams
* Cabinet
* Cwnsler Cyffredinol:

**Senedd Cymru Llywydd: Huw Irranca-Davies
* Prif Weithredwr a Chlerc:
* Aelodau (ASau): 2026
* Comisiwn y Senedd
* Etholaethau
* Etholiadau: 1999, 2003, 2007, 2011, 2016, 2021, 2026
* Cyfraith Gyfoes Cymru
* Mesurau rhestr
* Gorchymyn Cymhwysedd Deddfwriaethol
* Offerynnau Statudol

**Cymru o fewn y Deyrnas UnedigLlywodraeth ei Fawrhydi Ysgrifennydd Gwladol: Jo Stevens
* Swyddfa Cymru
* Prif Bwyllgor
* Pwyllgor Dethol
* Deddf Llywodraeth Cymru 2006
* Etholaethau'r DU
* Etholaethau Cymru
* Etholiadau: 1979, 1983, 1987, 1992, 1997, 2001, 2005, 2010, 2015, 2024

**Llywodraeth leol Prif ardaloedd
* Siroedd cadwedig
* Siroedd hynafol
* Cymunedau

**Gweithgarwch gwleidyddol Cenedlaetholdeb
* Datganoli Cymru
* Annibyniaeth Cymru
* Heddychiaeth
* Pleidiau gwleidyddol
* Polisïau unigryw Cymru
 |
|

---

gweld • sgwrs • golygu |

Fe wnaeth arolwg barn garn Redfield and Wilton ofyn y cwestiwn canlynol ym mis Rhagfyr 2023, "Pe bai refferendwm yfory gyda’r cwestiwn canlynol, sut fyddech chi’n pleidleisio? A ddylai Cymru fod yn wlad annibynnol?". Mae'r ffigyrau yn cynnwys tebygolrywdd o bleidleisio ac yn eithrio "ddim yn gwybod". Addaswyd ffigyrau YouGov i i dynnu y rhai nad oddent yn gwybod.

### Redfield & Wilton

(ffigyrau yn eithrio ddim yn gwybod)

|  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- |
| Mawrth 2025
 | **16-24** | **25-34** | **35-44** | **45-54** | **55-64** | **65+** |
| **Ie** | 53%
 | 72%
 | 45%
 | 35%
 | 41%
 | 20%
 |
| **Na** | 47%
 | 28%
 | 55%
 | 65%
 | 59%
 | 80%
 |

|  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- |
| Mai 2024
 | **16-24** | **25-34** | **35-44** | **45-54** | **55-64** | **65+** |
| **Ie** | 36%
 | 52%
 | 46%
 | 37%
 | 30%
 | 18%
 |
| **Na** | 64%
 | 48%
 | 54%
 | 63%
 | 70%
 | 82%
 |

|  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- |
| Mawrth 2024
 | **16-24** | **25-34** | **35-44** | **45-54** | **55-64** | **65+** |
| **Ie** | 40%
 | 44%
 | 52%
 | 29%
 | 22%
 | 29%
 |
| **Na** | 60%
 | 56%
 | 48%
 | 71%
 | 78%
 | 71%
 |

|  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- |
| Chwefror 2023
 | **16-24** | **25-34** | **35-44** | **45-54** | **55-64** | **65+** |
| **Ie** | 46%
 | 42%
 | 54%
 | 22%
 | 29%
 | 13%
 |
| **Na** | 54%
 | 58%
 | 46%
 | 78%
 | 71%
 | 87%
 |

|  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- |
| Ionawr 2024
 | **16-24** | **25-34** | **35-44** | **45-54** | **55-64** | **65+** |
| **Ie** | 59%
 | 53%
 | 47%
 | 29%
 | 28%
 | 16%
 |
| **Na** | 41%
 | 47%
 | 53%
 | 71%
 | 72%
 | 84%
 |

|  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- |
| Rhagfyr 2023
 | **16-24** | **25-34** | **35-44** | **45-54** | **55-64** | **65+** |
| **Ie** | 55%
 | 59%
 | 48%
 | 27%
 | 33%
 | 21%
 |
| **Na** | 45%
 | 41%
 | 52%
 | 73%
 | 67%
 | 79%
 |

|  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- |
| Awst 2023
 | **18-24** | **25-34** | **35-44** | **45-54** | **55-64** | **65+** |
| **Ie** | 58%
 | 60%
 | 45%
 | 28%
 | 34%
 | 29%
 |
| **Na** | 42%
 | 40%
 | 55%
 | 72%
 | 66%
 | 71%
 |

|  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Ebrill 2023
 | **16-17** | **18-24** | **25-34** | **35-44** | **45-54** | **55-64** | **65+** |
| **Ie** | 46%
 | 42%
 | 45%
 | 44%
 | 29%
 | 24%
 | 20%
 |
| **Na** | 54%
 | 58%
 | 55%
 | 56%
 | 71%
 | 76%
 | 80%
 |

### YouGov

|  |  |  |  |  |
| --- | --- | --- | --- | --- |
| Medi 2023
 | **16-24** | **25-49** | **50-64** | **65+** |
| **Ie** | 45%
 | 33%
 | 25%
 | 19%
 |
| **Na** | 55%
 | 67%
 | 75%
 | 81%
 |

|  |  |  |  |  |
| --- | --- | --- | --- | --- |
| Mai/Mehefin 2018
 | **18-24** | **25-49** | **50-64** | **65+** |
| **Ie** | 29%
 | 31%
 | 21%
 | 17%
 |
| **Na** | 71%
 | 69%
 | 79%
 | 83%
 |

## Arolygon annibyniaeth "0-10"

Gofynnwyd i ymatebwyr roi sgôr o 0–10. 0–4 Yn erbyn, 5 difater, 6–10 O Blaid. Dileu "Ddim yn Gwybod".

| Dyddiad
 | Cwmni
 | Sampl
 | Cyfanswm ffafriol
 | O blaid
 | Difater
 | Yn erbyn
 | Cyfanswm anffafriol
 |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 10
 | 9
 | 8
 | 7
 | 6
 | 5
 | 4
 | 3
 | 2
 | 1
 | 0
 |
| 10–15 Mai 2019
 | YesCymru / YouGov
 | 1,133
 | 36%
 | 14%
 | 4%
 | 5%
 | 6%
 | 7%
 | 17%
 | 5%
 | 6%
 | 6%
 | 2%
 | 28%
 | 47%
 |
| 9–12 Mai 2017
 | YesCymru / YouGov Archifwyd 1 Ebrill 2018 yn y Peiriant Wayback
 | 1,000
 | 29%
 | 10%
 | 2%
 | 6%
 | 6%
 | 5%
 | 18%
 | 4%
 | 6%
 | 7%
 | 5%
 | 31%
 | 53%
 |

## Arolygon annibynniaeth a datganoli

| Dyddiad
 | Cwmni
 | Cefnogi annibyniaeth (%)
 | Cefnogi mwy o bwerau i'r Senedd (%)
 | Cefnogi status quo (%)
 | Cefnogi llai o bwerau i'r Senedd (%)
 | Cefnogi diddymu y Senedd (%)
 | Difater/dim ateb/Arall (%)
 |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 28 Ionawr – 21 Chwefror 2021
 | BBC / ICM Unlimited
 | 14
 | 35
 | 27
 | 3
 | 15
 | 6
 |
| 29 Mai – 1 Mehefin 2020
 | ITV Cymru a Phrifysgol Caerdydd / YouGov
 | 16
 | 20
 | 24
 | 5
 | 22
 | 14
 |
| 4–22 Chwefror 2020
 | BBC / ICM
 | 11
 | 43
 | 25
 | 2
 | 14
 | 3
 |
| 7–23 Chwefror 2019
 | BBC / ICM
 | 7
 | 46
 | 27
 | 3
 | 13
 | 4
 |
| Rhagfyr 2018
 | SkyData
 | 8
 | 40
 | 23
 | 4
 | 18
 | 7
 |
| Chwefror 2017
 | BBC / ICM
 | 6
 | 44
 | 29
 | 3
 | 13
 | 4
 |
| Chwefror 2016
 | BBC / ICM
 | 6
 | 43
 | 30
 | 3
 | 13
 | 4
 |
| Chwefror 2015
 | BBC / ICM
 | 6
 | 40
 | 33
 | 4
 | 13
 | 4
 |
| Medi 2014
 | BBC / ICM
 | 3
 | 49
 | 26
 | 2
 | 12
 | 6
 |
| Chwefror 2014
 | BBC / ICM
 | 5
 | 37
 | 28
 | 3
 | 23
 | 5
 |
| 2013
 | BBC / ICM
 | 9
 | 36
 | 28
 | 2
 | 20
 | 4
 |
| 2012
 | BBC / ICM
 | 7
 | 36
 | 29
 | 2
 | 22
 | 4
 |
| 2011
 | BBC / ICM
 | 11
 | 35
 | 18
 | 17
 | 15
 | 4
 |
| 2010
 | BBC / ICM
 | 11
 | 40
 | 13
 | 18
 | 13
 | 4
 |

## Annibyniaeth vs Dim datganoli

| Dyddiad
 | Cwmni
 | Sampl
 | Annibyniaeth (gan gynnwys is-samplau)
 | Dim llywodraeth ddatganoledig (gan gynnwys is-samplau)
 | Difater / dim ateb *(%)* |
| --- | --- | --- | --- | --- | --- |
| Cyfanswm (%)
 | *Ceidwadwyr* *(%)* | *Llafur* *(%)* | *Democratiaid Rhyddfrydol* *(%)* | *Plaid Cymru* *(%)* | Cyfanswm (%)
 | *Ceidwadwyr (%)* | *Llafur (%)* | *Democratiaid Rhyddfrydol (%)* | *Plaid Cymru (%)* |
| 29 Mai – 1 Mehefin 2020
 | ITV Cymru / YouGov / Prifysgol Caerdydd Archifwyd 4 Medi 2020 yn y Peiriant Wayback
 | 1,021
 | 33%
 | 12%
 | 45%
 | 39%
 | 87%
 | 45%
 | 79%
 | 35%
 | 53%
 | 4%
 | 21%
 |

## Gweler hefyd

### Arolygon barn

* Etholiad nesaf Senedd Cymru
* Etholiad cyffredinol nesaf y Deyrnas Unedig yng Nghymru

### Cymru

* Ymgyrch i ddod â theitl Tywysog Cymru i ben

* Datganoli Cymru
* Annibyniaeth i Gymru
* Mudiad gweriniaethol Cymru
* Rhestr o Gymry a wrthododd "Anrhydedd Brydeinig"
* Rhestr mudiadau Cymru
* Gwleidyddiaeth Cymru

### Gwledydd eraill

* Annibyniaeth yr Alban
* Arolygon barn ar annibyniaeth yr Alban
* Iwerddon unedig
* Arolygon barn ar Iwerddon Unedig
* Llydaw Unedig
* Datganoli Cernyw

## Cyfeiriadau