Idris Williams (19 (or 9) April 1836 – 4 November 1894) was an educationalist, prominent Congregationalist, and Liberal councillor for the Cymmer division of the Glamorgan County Council, South Wales.

[3] Williams received very little formal education and at the age of nine he went to work as a haulier at George Insole & Son's Cymmer Colliery.

The first was his connection with the pre-industrial society of the valley as the heir to Porth Farm, an agricultural holding that disappeared with the advent of industrialisation (although the former farmhouse, where his younger brother Levi Williams lived, survived next to the railway station in the centre of Porth).

The second factor was the considerable wealth that he accrued after coal mining operations commenced on the land which formerly formed part of the Porth Farm.

[8] Williams died suddenly in Porth on 4 November 1894 and was buried four days later at the Cymmer Independent Chapel graveyard[9][10] after "a vast concourse of people [had] assembled to pay their last tokens of respect and esteem.