Penryn (meaning 'promontory') is a civil parish and town in Cornwall, England, United Kingdom. It is situated on the Penryn River about northwest of Falmouth. The population was 7,166 in the 2001 census.
Penryn is one of Cornwall's most ancient towns with a wealth of history . These lands appear in Domesday Book under the name of "Trelivel". Penryn was founded in 1216 by the Bishop of Exeter. The borough was enfranchised and its Charter of Incorporation was made in 1236. The contents of this Charter were embodied in a confirmation by Bishop Walter Bronescombe in the year 1259. In 1265, a religious college, called Glasney College was built in Penryn for the Bishop of Exeter to develop the church's influence in the far west of the diocese. In 1374, the chapel of St Thomas (sometimes called St Mary's) was opened. Standing at the head of the Penryn River, Penryn occupies a sheltered position and was a port of some significance in the 15th century. After the Dissolution of the Monasteries by Henry VIII and the disestablishing of the Roman Catholic church, Glasney was dissolved and demolished in 1548 during the brief reign of Edward VI, the first Protestant Duke of Cornwall, afterwards King of England. The dissolution of Glasney College helped trigger the Prayer Book Rebellion of 1549. The loss of Glasney and the defeat of the 1549 rebellion proved to be a turning point in the history of the town from which Penryn has never recovered.
By the mid 17th century the port was thriving with the trade in Cornish fish, tin and copper. However, Penryn lost its custom house and market rights to the new town of Falmouth as a direct result of supporting the Parliamentary side in the English Civil War (1642–48). The Killigrews of Arwenack were more skilful turncoats, and as their new town grew so the older port of Penryn declined from the 17th century right up to today.
In the early 19th century, granite works were established by the river and large quantities of the stone were shipped from its quays for construction projects both within the UK and abroad.
The A39 road, which begins in Bath and is about long, once passed through Penryn towards the end of its route in nearby Falmouth, but in 1994 was diverted around the town when the Penryn Bypass was opened, incorporating a stretch of new road along with upgrading to an existing road.