| Country: | Wales |
| Welsh Name: | Pontsenni |
| Constituency Welsh Assembly: | Brecon & Radnorshire |
| Static Image: | Maescar - Pont Senni.jpg |
| Static Image Width: | 240px |
| Static Image Caption: | Sennybridge, view southwest down High Street |
| Official Name: | Sennybridge |
| Coordinates: | 51.946°N -3.569°W |
| Community Wales: | Maescar |
| Unitary Wales: | Powys |
| Lieutenancy Wales: | Powys |
| Constituency Westminster: | Brecon & Radnorshire |
| Post Town: | BRECON |
| Postcode District: | LD3 |
| Postcode Area: | LD |
| Dial Code: | 01874 |
| Os Grid Reference: | SN9228 |
Sennybridge (Welsh: Pontsenni) is a village in Powys, Wales, in the historic county of Brecknockshire, situated some 42miles from Cardiff and 31miles from Swansea. It lies 9miles west of Brecon on the A40 trunk road to Llandovery, at the point where the Afon Senni flows into the Usk. It is in the community of Maescar.
One of the factors which influenced the growth of Sennybridge was the establishment of the Neath and Brecon Railway which opened a station in the adjoining village of Defynnog in 1867.[1] The promoter and contractor of the railway, John Dickson, also made a start on constructing a railway north from Sennybridge that would have linked the Neath and Brecon Railway to the Central Wales Line at Llangammarch Wells but work was suspended on his bankruptcy in 1867 and never resumed. The partially completed earthworks can still be seen in the countryside north of Sennybridge.
An extensive area of land to the north of Sennybridge is used by the Ministry of Defence for military training purposes. Sennybridge Camp and Army Field Training Centre, known as SENTA, is one of the major bases for Infantry Warfare Training by the British Army in the UK.
Sennybridge's primary school, which houses a Welsh Language Unit, utilises the old Secondary Modern buildings in the village. Although the school is in Sennybridge, it continued to be named Defynnog Primary School until the 1980s when its name was changed to Sennybridge Primary School.