Dwyfor Meirionnydd is a constituency of the House of Commons of the Parliament of the United Kingdom (at Westminster), held by Liz Saville Roberts of Plaid Cymru.

At the 2023 Periodic Review of Westminster constituencies and under the June 2023 final recommendations of the Boundary Commission for Wales, the constituency retained its name and gained wards in boundary changes first used for the 2024 United Kingdom general election.

The seat is composed of the following electoral wards: 2010–2024: The Gwynedd wards of Aberdaron, Aberdyfi, Abererch, Abermaw, Abersoch, Bala, Botwnnog, Bowydd and Rhiw, Brithdir and Llanfachreth/Ganllwyd/Llanelltyd, Bryn-crug/Llanfihangel, Clynnog, Corris/Mawddwy, Criccieth, Diffwys and Maenofferen, Dolbenmaen, Dolgellau North, Dolgellau South, Dyffryn Ardudwy, Efail-newydd/Buan, Harlech, Llanaelhaearn, Llanbedr, Llanbedrog, Llandderfel, Llanengan, Llangelynin, Llanuwchllyn, Llanystumdwy, Morfa Nefyn, Nefyn, Penrhyndeudraeth, Porthmadog East, Porthmadog West, Porthmadog-Tremadog, Pwllheli North, Pwllheli South, Teigl, Trawsfynydd, Tudweiliog and Tywyn.

2024–present: As above, plus the Gwynedd wards of Bethel & Felinheli, Caernarfon Town Central, Clynnog, Cwm-y-Glo, Deiniolen, Hendre, Llanberis, Llanllyfni, Llanrug, Llanwanda, Menai, Peblig, Penygroes, Tryfan, Bontnewydd, and Groeslon, and the Denbighshire ward of Edeirnion.

This article relating to a constituency of the Parliament of the United Kingdom or its predecessors is a stub.