Knighton (pronounced //naɪtɒn//) (Welsh: Trefyclawdd or Trefyclo) is a small town situated chiefly in Powys, Wales.

Lying on the River Teme, the town straddles the English-Welsh border; Knighton railway station, as well as a small part of the town's built-up area, lie in Shropshire, England.

The name Knighton probably derives from the Old English words cniht and tūn meaning, respectively, ". . . a soldier, personal follower, young man, servant, thane, freeman" and ". . . farm, settlement, homestead". This implies that the settlement was perhaps founded as the result of a grant of land to freemen. By contrast the Welsh name (Tref-y-Clawdd) is more straightforward and translates simply as the town on the dyke.

History
Inevitably, Knighton's earliest history is obscure but there are local clues: Caer Caradoc (an Iron Age hillfort associated with Caradoc or Caractacus) is 2 miles (3 km) away and just off the road towards Clun. Watling Street, a Roman road, passes a few miles to the east at Leintwardine. Knighton is known for a well preserved section of Offa's Dyke. Intriguingly, Wat's Dyke also runs parallel to Offa's Dyke and a few miles to the east. An earthwork that runs north-south along the English/Welsh border from Basingwerk near Holywell to Oswestry. The dykes aside, two Norman castles, constructed in the 12th century, are the oldest survivals in modern Knighton. The town became a borough in 1203, with a charter permitting a weekly market and annual fair. The castle was besieged by Owain Glyndŵr in 1402 and the castle and much of the town were destroyed. The major battle of the rebellion was fought at Pilleth (Welsh: Bryn Glas) 3 miles (5 km) south of the town in the same year.

The town’s church dates from the 11th century, but much of it was rebuilt in the 19th century. It is one of only two in Wales dedicated to St Edward; the patron saint of England before St George. This dedication to an English saint is a symptom of a dual English/Welsh nature of the town that was not legally resolved until 1535 when Knighton was finally confirmed as part of Wales by the Acts of Union.

Knighton first prospered as a centre of the wool trade in the 15th century, and was later an important point on the two drover routes from Montgomery to Hereford, and from London to Aberystwyth. Otherwise, Knighton was remote from the centres of commerce. It seemed likely that the railway revolution would also fail to reach the town; the 1840s and 1850s saw considerable railway building right across Great Britain but Radnorshire had a small population and little industry. The construction of the railway was made economically viable - just - by an entrepreneurial driveto connect the Mumbles and Milford Haven with the cities and factories of the industrial Midlands.