Y gwahaniaeth rhwng diwygiadau o "Sir Forgannwg (etholaeth seneddol)"

|style="background-color: {{Conservative Party (UK)/meta/color}}" |
| [[Edwin Wyndham-Quin]]
| [[Y Blaid Geidwadol (DU)|Ceidwadol)]]
|-
| 1851
|style="background-color: {{Conservative Party (UK)/meta/color}}" |
| [[George Tyler]]
| [[Y Blaid Geidwadol (DU)|Ceidwadol)]]
|-
| 1857
Defnyddiwr anhysbys