Alternatively, one can think of the constituency as being divided between a 'suburban' district in the south and communities that grew in the industrial revolution to the north; the Southern area, particularly between Church Village and Llantrisant, contains much new residential and light industrial development, and benefits from good transport links due to its proximity to the M4. This section has a growing population and is an important 'dormitory' for Cardiff. The Northern parts, particularly Tonyrefail and the northern end of Pontypridd town consists of large sections of 19th century housing and suffered high unemployment in the 1980s as the old industries closed. However, in recent years, economic recovery has been firm, especially considered with neighbouring constituencies to the north.
The Pontypridd constituency was created in its original form from parts of the old South Glamorganshire & East Glamorganshire constituencies as part of the Representation of the People Act 1918 (sometimes referred to as 'The Fourth Reform Act') which granted virtually all men over 21 the right to vote, extended voting rights to women over 30 years of age, & increased the number of the now abolished University constituencies. Part of this Act also effected a 'General Redistribution of Seats' on an 'equitable basis'. It originally included the old Borough of Cowbridge, the Cowbridge Rural District (which included Ystradowen, Bonvilston, St Athan, Llantwit Major & Llandow) & the Urban District of Pontypridd plus the Rural District of Llantrisant & Llantwit Fardre. The constituency remained unchanged from this form until the Third Periodic Parliamentary Boundary Review's proposals were implemented in 1983. This removed Cowbridge Borough and the southern part of the former Cowbridge Rural District, placing them in the Vale of Glamorgan constituency, and additionally moving the communities of Llanharry, Llanharan, and Brynna (i.e. the northern part of the former Cowbridge RDC) into the Ogmore constituency. However, the communities of Creigiau and Pentyrch were added to the seat at this time.
Like many seats in South Wales, Pontypridd has been held by the Labour party for over 100 years. In all the years since the Labour Party first took the seat in the 1922 by-election, its smallest majority has been the 2,785 (7.6%) by which it held the seat over the Liberal Democrats in 2010. Generally its majorities have been considerably higher.
a In 1983 the Third Periodical Boundary Review report made major changes to the constituency, removing the Cowbridge community & placing it in the new Vale of Glamorgan seat & also by removing the Llanharry & Llanharan communities to the Ogmore seat. However, the Pentyrch & Creigiau communities were added to the new seat from the old Barry seat, to give a new seat with nearly 15,000 fewer electors.
b This was and still is the largest number of electors for the Pontypridd constituency in any of its forms.
c Arthur Pearson's initial selection following a closely contested process at a selection conference at Pontyclun occurred only after several rounds of voting, and he was finally chosen against the prominent local miners' agent W. H. May on 15 January 1938.