The community includes the nearby village of Coed Talon, to the east, and Rhydtalog, to the south-west on the Denbighshire border.

According to the United Kingdom Census 2021, 20.7 per cent of all usual residents aged 3+ in Treuddyn can speak Welsh.

[4] 31.4 per cent of the population noted that they could speak, read, write or understand Welsh.

[5] The 2011 census noted 24.4 per cent of all usual residents aged 3 years and older in the village could speak Welsh.

[4] The 2021 Census noted that 97.4 per cent of Treuddyn's population was born in the United Kingdom.