St David's church is located on the north-east side of Gyfeillion Road, between it and the railway. A church of St David (in 'Rhondda valley') is listed as having received a grant for its building in 1850-2, and then having it withdrawn after 'approved plans were not adhered to'. The Ordnance Survey County Series first-edition 25-inch map of 1878 shows a church at this location as St David's Church (chapel of ease). However, the second-edition of 1900 shows a larger church, on a different plan, dedicated to St David, on the same site. If the earlier structure refers to the 1850s building then the church was initially built at the time of local industrial development with the sinking of coal mines and the establishment of Hopkinstown.
The present church was built in 1896 to designs of E.M.Bruce Vaughan. It is built of rock-faced Pennant sandstone with Bath stone dressings, in Early English style incorporating Decorated windows. It comprises nave with lean-to south aisle built 1897-8, and lower chancel with lean-to south chapel (1910-12), west double bell-gable, and entry to church through a narthex-like porch on the west gable.
Inside, the arcade piers alternate round and quatrefoil. The font, by Bruce Vaughan, was carved by Clarke of Llandaff. The pulpit, of Penarth alabaster, is by G.E.Halliday (1914). Stained glass includes work by R.J.Newbery.

Sources:
churchplansonline.org
J.Newman, Buildings of Wales: Glamorgan (1995), pp.365-6.
http://www.jlb2011.co.uk/walespic/churches/hopkinstown1.htm (images)
OS 25-inch maps: Glamorganshire sheet XXVIII.10.

David Leighton, RCAHMW, 16 January 2015