Llanfrynach is a village and community in the county of Powys, Wales, and the historic county of Brecknockshire. The population of the community as taken at the 2011 census was 571. It lies just to the southeast of Brecon in the Brecon Beacons National Park. The village sits astride the Nant Menasgin, a right bank tributary of the River Usk. The B4558 passes just to its north and the Monmouthshire and Brecon Canal also passes around the village. The Welsh name signifies the 'church of Brynach'. The community includes the hamlets of Llanhamlach and Groesffordd.
The Cefn Brynich Canal Bridge Aqueduct over the Usk is a Grade II* listed structure.
- "Community population 2011". Retrieved 10 November 2015.
- Ordnance Survey Explorer map OL12 'Brecon Beacons National Park: western area'
- Owen, H.W. & Morgan, R. 2007 'Dictionary of the Place-names of Wales' Gomer Press, Ceredigion
- "The Cefn Brynich Canal Bridge Aqueduct, Llanfrynach". British Listed Buildings. Retrieved 14 December 2013.
- "The County of Powys (Electoral Arrangements) Order 1998". Legislation.gov.uk. Retrieved 13 October 2018.