Meirionnydd Nant Conwy was a constituency represented in the House of Commons of the Parliament of the United Kingdom.

The Meirionnydd Nant Conwy Welsh Assembly constituency was created with the same boundaries in 1999.

For the entire period of its existence, it was represented by Plaid Cymru, and was generally regarded as a safe seat.

It had the lowest population of any constituency in England or Wales, and also had the second highest proportion of Welsh-speaking voters.

This was a mainly rural area containing small towns and villages such as Dolgellau, Blaenau Ffestiniog, Bala, Betws-y-Coed, and Llanrwst.