Dinas Mawddwy is a village in Gwynedd, Wales.
It is situated within the SY20 postcode district, which is within the Machynlleth post town.
SY20 is the only postcode district within the Machynlleth post town.
The Machynlleth post town is within the Shrewsbury postcode area.
Administrative Ward: Corris/Mawddwy
Administrative District: Gwynedd
Country: Wales
UK Parliament: Dwyfor Meirionnydd